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ILLINOIS    BIOLOGICAL 
MONOGRAPHS 

Vol.  IV  April,  19 1 8  No.  4 


Editorial  Committee 


Stephen  Alfred  Forbes  William  Trelea  e 

Henry  Baldwin  Ward 


Published  under  the 

Auspices  of  the  Graduate  School  by 

THE  University  of  Illinois 


COPYKIGHT,  1918  BY  THE  UNIVERSITY  O?  IlLIKOIS 

Distributed  May  31, 1919 


NORTH  AMERICAN 

PSEUDOPHYLLIDEAN  CESTODES 

FROM  FISHES 


WITH  THIRTEEN  PLATES 


BY 

ARTHUR  REUBEN  COOPER 


Qmtributions  from  the 

Zoological  Laboratory  of  the  University  of  lUiDois 

under  the  direction  of  Henry  B.  Ward,  No.  127 


COPYRIGHT,  I9I9 
BY  THE  UN-IVERSITV  OF  ILLINOIS 


TABLE  OF  CONTENTS 

Pages 

Introduction 7 

Historical  Data 8 

Explanation  of  Terms 10 

Key  to  the  Families,  Subfamilies,  Genera  and  Species 11 

Order  PSEUDOPHYLLIDEA 13 

Family  DIPHYLLOBOTHRIIDAE 15 

Ligulinae  Luhe  1899 •. 16 

LigulaBloch  1782 17 

Ligula  intestinalis  (Linnaeus  1758) 18 

Schistocephalus  Creplin  1829 30 

Schistocephalus  solidus  (O.  F.  Miiller   1776) 30 

Haplobothriinae  Cooper  1917 42 

Haplobothrium  Cooper  1914 43 

JJaplohothrium  globuliforme  Cooper  1914 44 

Cyathocephalinae  Liihe  1899,  e.  p 53 

Cyathocephalus  Kessler  1868 53 

Cyalhocephalus  americanus  Cooper  1917 53 

Bothrimonus  Duvernoy  1842 62 

Bothrimonus  intermedius  Cooper  1917 , 63 

Marsipometrinae  Cooper  1917 70 

Marsipometra  Cooper  1917 70 

Marsipometra  hastata  (Linton  1897) 71 

Triaenophorinae  Luhe  1899 „ 81 

Triaenophorus  Rudolphi  1793 81 

Triaenophorus  sp.  larv 82 

Fistulicola  Liihe  1899 88 

Fishdicola  plicatus  (Rudolphi  1819) 89 

FamUy  PTYCHOBOTHRIIDAE 93 

Ptychobothriinae  Liihe  1899 94 

Bothriocephalus  Rudolphi  1808 95 

BothriocepJialus  scorpii  (Miiller  1776) 96 

Dibothrium  angustatum  (Rudolphi)  112 

Bothriocephalus  claviceps  (Goeze  1782) 114 

Bothriocephalus  cuspidatus  Cooper  1917 123 

Bothriocephalus  manubriformis  (Linton  1889) 133 

Dibothrium  laciniatum   (Linton) 145 

Bothriocephalus  histiophorus  (Shipley)  147 

Bothriocephalus  occidentalis  (Linton  1898) 149 

Clestobothrium  Liihe  1899 153 

Clestobothrium  crassiceps  (Rudolphi  1819) 154 

Amphicotylinae  Liihe  1902 171 

Abothrium  van  Beneden  1871 171 

Abothrium  rugosum  (Bats6h  1786) 172 

Abothrium  crassum  (Bloch  1779) 186 


2941                               ILLINOIS  BIOLOGICAL  MONOGRAPHS  6 

Bibliography 201 

Explanation  of  Plates 211 

Index  of  Hosts 237 

Index 241 


295]  PSEUDOPHYLLIDEA  FROM  FISHES— COOPER 


INTRODUCTION 

Soon  after  commencing  the  study  of  Haplohothrium  globuliforme  Cooper  the 
writer  (1914,  1914a)  saw  that,  apart  from  the  early  and  somewhat  brief 
reports  and  descriptions  by  Leidy  and  the  later,  but  yet  pioneer  work  of  Linton 
on  both  marine  and  fresh-water  species,  very  Uttle  had  been  done  on  the  mem- 
bers of  the  order  in  America.  Consequently  the  desire  for  an  opportunity 
to  work  up  other  species  which  had  in  the  meantime  been  collected  at  the 
Canadian  Lake  Biological  Station  on  Georgian  Bay,  located  at- Go-Home  Bay, 
Muskoka  District,  Ontario,  and  at  the  Marine  Biological  Station  at  St.  And- 
rews, New  Brunswick,  grew  with  the  feeling  that  something  of  a  comprehensive 
nature  ought  to  be  undertaken  in  order  not  only  to  ascertain  to  what  extent 
European  species  are  to  be  found  in  this  continent,  but  also  to  locate  properly 
in  the  classification  at  least  some  of  the  new  forms  formerly  described,  especially 
by  Linton.  Altho  the  material  then  at  hand  was  investigated  to  a  certain 
extent  at  the  University  of  Toronto,  it  was  not  until  the  writer  came 
to  the  University  of  Illinois  that  it  was  studied  at  all  thoroly  with  the  aid  of 
other  material  for  comparison  from  the  collection  of  the  University  of  IlUnois, 
under  the  care  of  Professor  Henry  B.  Ward, 

Supplementary  material,  which  in  many  cases  was  all  that  was  available, 
was  obtained  by  Professor  Ward  from  the  United  States  National  Museum 
and  the  Bureau  of  Animal  Industry,  but  apart  from  a  few  vials  no  European 
specimens  could  be  procured,  owing  to  the  present  international  conflict.  On 
account  of  the  lack  of  the  latter  most  of  the  determinations  have  been  made 
with  the  aid  of  the  literature  only,  a  fact  which  the  writer  feels  may  necessitate 
future  changes  in  connection  with  a  few  species  which  have  been  more  or  less 
tentatively  regarded  to  be  the  same  as  those  in  Europe.  In  all  cases,  however, 
the  specific  details  of  the  American  forms  have  been  emphasized,  so  that  if 
changes  have  to  be  made  later,  the  basis  for  such  will  be  at  hand.  The  writer 
would  like  to  point  out  in  this  connection  the  comparative  lack  from  a  systema- 
tic standpoint  of  adequate  descriptions  of  many  of  the  European  species  which 
have  been  known  for  many  years.  It  was  this  fact  which  in  the  absence  of 
the  original  material  for  comparison  made  the  present  work  one  attended  with 
not  a  little  difficulty. 

In  the  main  the  classification  of  the  order  adopted  by  the  writer  is  that 
proposed  by  Luhe  (1902)  and  later  (1910)  retained  with  only  a  few  modifica- 
tions. The  family  of  the  Caryophyllaeidae  is,  however,  not  included,  so  that 
the  order  is  considered  to  be  rather  that  of  Carus  (1863),  with  Liihe's  later 
conceptions  of  the  other  famiHes.  One  of  the  latter  must  now  again  be  modified 
considerably  owing  to  the  present  study  of  two  quite  aberrant  species,  namely, 
Haplobothrium  globuliforme  Cooper  and  Marsipometra  hastata  (Linton)  which 
have  been  found  by  the  writer  to  be  very  disturbing  to  the  classification. 

The  writer  wishes  here  to  tender  his  thanks  in  the  first  place  to  the  Biological 
Board  of  Canada  for  placing  means  and  facilities  at  his  disposal  in  connection 


8  ILLINOIS  BIOLOGICAL  MONOGRAPHS  [296 

with  his  earlier  collecting  at  the  above-mentioned  Canadian  Biological  Stations; 
to  the  University  of  Illinois  for  the  opportunity  of  collecting  further  material 
at  the  Marine  Biological  Laboratory  at  Woods  Hole,  Massachusetts,  and  at 
the  Harpswell  Laboratory,  South  Harpswell,  Maine,  during  the  summer  of 
1916,  and  to  the  staffs  of  these  institutions  as  well  as  to  that  of  the  Marine 
Laboratory  of  the  United  States  Bureau  of  Fisheries  at  Woods  Hole  for  assis- 
tance and  direction  in  connection  with  the  same;  to  the  Smithsonian  Institute 
and  the  Bureau  of  Animal  Industry,  from  whom  valuable  material  was  obtained 
for  comparison,  in  the  latter  case  thru  the  kind  offices  of  Dr.  C.  W.  Stiles  of 
the  Hygienic  Laboratory,  Washington;  and  to  the  following  investigators 
for  alcohoUc  specimens:  Professor  O.  Fuhrmann,  University  of  Neuchatel, 
Switzerland,  Professor  Edwin  Linton,  Washington  and  Jeflferson  College,  Pro- 
fessor E.  M.  Walker,  University  of  Toronto,  Dr.  H.  J.  VanCleave,  University 
of  lUinois,  Dr.  G.  R.  LaRue,  University  of  Michigan,  Dr.  A.  S.  Pearse,  Univer- 
sity of  Wisconsin,  and  Messrs.  H.  R.  Hill  and  R.  P.  Wodehouse. 

Finally  to  Professor  H.  B.  Ward  the  writer  wishes  to  express  his  sincere 
indebtedness  not  only  for  the  use  of  his  extensive  private  library  and  collections 
and  for  the  procuring  of  rare  books  and  specimens,  but  for  his  constant  and 
stimulative  interest  in,  and  valuable  criticism  of,  the  work  which  has  resulted 
in  the  following  paper. 

HISTORICAL  DATA 

Apart  from  Gmelin's  (1790)  collecting  together  the  data  given  by  the  older 
writers  such  as  Linnaeus,  Pallas,  Miiller,  Goeze,  Bloch,  Fabricius,  Batsch, 
Schrank  and  Abildgaard,  and  Zeder's  (1800,  1803)  treatises,  the  first  most 
important  work  on  the  bothriocephalid  cestodes  was  the  Entozoorum  Historia 
Naturalis  by  Rudolphi  (1808-1810).  In  this  he  reviewed  the  earUer  literature, 
making  valuable  comments  on  the  same,  and  described  species  of  Ligula, 
Triaenophorus  and  Bothriocephalus,  the  latter  name  being  used  for  the  first 
time.  While  Lamarck  (1816)  dealt  with  only  the  more  common  species, 
Rudolphi  in  his  second  work  of  major  importance,  the  Entozoorum  Synopsis 
(1819),  made  some  corrections  of  his  earlier  publication  and  further  contribu- 
tions in  the  way  of  a  few  new  species.  F.  S.  Leuckart  (1819),  who  did  not  receive 
Rudolphi's  Entozoorum  until  after  his  own  work  was  in  print,  dealt  only  with 
species  of  the  genus  Bothriocephalus  as  conceived  by  Rudolphi,  which  then  con- 
tained members  not  only  of  the  Pseudophyllidea  but  also  of  the  TetraphyUidea 
and  the  Trypanorhyncha.  Nitzsch  (1824)  briefly  defined  the  species  of  the 
same  genus,  while  later  Creplin  (1839)  dealt  with  them  more  in  detail  and 
erected  the  new  genus  Schistocephalus.  Drummond  (1838)  was  one  of  the 
first  to  report  bothriocephalids  from  the  British  Isles,  while  BeUingham  (1844) 
and  Thompson  (1844)  made  further  contributions,  all  three  deahng  with  forms 
from  Ireland.  Eschricht  (1841)  pubhshed  some  of  the  earliest  data  on  the 
internal  anatomy  of  the  group,  and  KoUiker  (1843)  made  a  study  of  the 
development  of  the  eggs  of  a  few  species.  The  next  and  perhaps  most  impor- 
tant work  was  that  by  Dujardin  (1845)  who,  while  following  Rudolphi  in  the 


297)  PSEU DOPEY LLIDEA  FROM  FISHES— COOPER  9 

main,  made  many  valuable  additions  from  original  observations.  Van  Beneden 
(1849,  1850)  first  essayed  to  erect  a  more  comprehensive  classification  than 
had  hitherto  been  used,  and  Diesing  (1850)  went  much  farther  in  his  Subtribe  I, 
Gymnobothria,  of  Tribe  IV,  Bothriocephalidea,  of  Suborder  I,  Aprocta,  of 
Order  IV,  Cephalocotylea.  Baird  (1853)  reverted  to  Rudolphi's  brief  system,' 
in  Hsting  forms  from  the  British  Museum.  Wagener  in  two  pap)ers  (1854, 
1857)  pubHshed  studies  on  the  development  which  even  to-day  are  models  of 
careful  work  and  excellent  illustrating.  Leidy  (1855,  1856)  was  the  first  to 
report  forms  from  America,  while  Weinland  (1858)  made  a  few  references  to 
bothriocephalids. 

Then,  until  Diesing  (1863)  revised  his  classification  nothing  of  systematic 
importance  appeared.  Olsson  (1867)  was  one  of  the  first  to  report  species 
from  the  Scandinavian  countries;  later  (1876,  1893)  he  made  further  contri- 
butions from  the  same  region.  After  Willemoes-Suhm's  (1869)  studies  on  the 
development  of  Schistocephalus  dimorphus,  came  Duchamp's  (1876)  and 
Donnadieu's  (1877)  classical  experiments  on  the  life-histories  of  the  ligules. 
Linstow  (1878)  brought  together  in  a  list  the  forms  known  up  to  that  time. 
A  few  years  later  Fraipont  (1880,  1881)  published  studies  on  the  excretory 
system  of  a  number  of  species  which  even  to-day  are  perhaps  the  most  impor- 
tant contributions  in  that  direction.  The  nervous  system  was  made  the 
object  of  special  inquiry  by  Lang  (1881),  while  later  it  was  dealt  with  more 
at  length  by  Niemiec  (1888)  and  Cohn  (1898).  After  a  period  in  which  such 
works  as  those  with  studies  on  development  by  Moniez  (1881),  Zschokke 
(1884)  and  Schauinsland  (1885)  are  prominent,  come  the  next  reports 
of  species  from  America,  namely,  those  contained  in  Linton's  first  paper  (1889). 
The  latter  was  followed  by  a  second  (1890),  containing  extensions  of  the  first, 
and  later  by  others  (1891,  1897,  1901  and  1901a)  dealing  with  a  variety  of 
forms  from  marine  and  fresh-water  fishes.  Further  anatomical  studies  by 
Lonnberg  (1891),  Kraemer  (1892),  Matz  (1892)  and  Zernecke  (1895)  lead  on 
to  Monticelli's  (1892)  classification,  which  was  the  most  important  since  the 
time  of  Diesing,  altho  Perrier  (1878)  had  in  the  meantime  voiced  his  ideas  along 
that  line.  The  next  in  order  is  Ariola's  (1896)  division  of  the  family  "  Bothrio- 
cephalidae,"  in  which  incidentally  were  yet  to  be  found  errors  regarding  the 
position  of  the  bothria. 

Beginning  with  1894  and  continuing  to  1900  there  was  in  progress  the 
publication  of  Braun's  Cestodes  in  Bronn's  Tierreich,  which  is  by  far  the  most 
comprehensive  work  on  the  group,  since  it  brings  together  the  substance  of  the 
most  important  of  the  earlier  works  on  the  morphology  as  well  as  the  system 
of  the  order.  One  of  the  first  papers  by  Liihe,  who  did  recent  important  work 
on  the  group,  was  that  (1896)  in  which  he  dealt  with  the  nervous  system  of 
Ligula.  Further  study  led  him  to  pubhsh  a  few  years  later  (1899)  his  first  classi- 
fication, which  was  adopted  by  Braun  (1894-1900).  In  the  meantime  Lonn- 
berg (1897)  made  valuable  contributions  to  the  knowledge  of  the  phylogeny 
of  the  parasitic  flatworms;  while  Gamble  (1896)  and  Perrier  (1897)  had  erected 
systems  of  classification  which,  however,  do  not  have  nearly  as  much  in  their 


10  ILLINOIS  BIOLOGICAL  MONOGRAPHS  [298 

favor  for  general  acceptance  as  does  that  by  Liihe.  In  1900  Ariola  brought 
out  his  revision  of  the  family  of  the  Bothriocephalidae,  which,  however,  was 
shown  by  Liihe  (1901)  to  be  rather  of  the  nature  of  a  compilation,  in- 
volving at  the  same  time  several  omissions,  than  a  distinct  advance  in  our 
knowledge.  In  1901  there  appeared  in  Lankester's  Treatise  on  Zoology 
Benham's  classification  of  Cestodes  which  professedly  follows  the  earlier  works 
of  Railliet  and  Blanchard.  Liihe's  (1902a)  revision  of  the  bothriocephaUd 
system  comes  next  in  order.  It  is  this  newer  system,  only  slightly  modified 
in  1910,  that  is  accepted  by  the  writer  with  several  necessary  modifications 
which  are  dealt  with  below. 

From  1902  until  Die  Siisswasserfauna  Deutschlands  was  published,  the 
literature  on  the  group  consists  mostly  of  papers  on  individual  species  or  mere 
listings.  Spengel's  (1905)  paper  on  Die  Monozootie  der  Cestoden  ought, 
however,  to  be  mentioned,  since  it  is  one  of  the  latest  discussions  of  a  question 
which  occupied  a  good  deal  of  the  attention  of  many  of  the  older  writers. 
Finally  Ward  (1910)  and  the  writer  (Cooper,  1914a,  b)  made  the  latest  addi- 
tions to  the  American  Uterature,  while  Stiles  and  Hassall  won  the  gratitude  of 
the  yoimger  workers  at  least  by  their  pubHcation  of  the  section  of  the  Index- 
Catalogue  of  Medical  and  Veterinary  Zoology  on  Subjects:  Cestoda  and 
Cestodaria  which  the  writer  has  foimd  of  inestimable  value  in  the  pursuit 
of  his  studies. 

EXPLANATION  OF  TERMS 

Owing  to  the  fact  that  not  a  little  confusion  exists  in  the  earliest  Uterature 
regarding  the  terms  of  orientation  used  for  the  cestode  body,  the  writer  wishes 
here  to  explain  those  that  will  be  employed  in  the  specific  descriptions  below. 

Even  much  later  than  the  time  of  Diesing  (1850)  the  word  "lateral"  was 
used  to  refer  to  the  flat  surfaces  of  the  typical  strobila,  while  "marginal"  was 
and  is  even  yet  perfectly  clear  in  meaning;  but  from  the  standpoint  of  bilateral 
symmetry  both  words  may  mean  the  same  thing.  Here  they  are  considered 
to  be  synonymous  and  are  used  to  refer  to  any  part  which  is  situated  in  or  at 
the  edges  of  the  strobila  and  consequently  of  the  individual  proglottides.  On 
the  other  hand,  the  word  "surficial"  is  adapted  from  geology  to  take  the  place 
of  the  word  "  flachenstandig  "  which  is  used  freely  in  Liihe's  papers  to  mean  that 
the  structures  in  question  are  located  on  the  broad,  flat  surfaces  of  the  chain. 
As  is  customary,  the  latter  are  considered  to  be  dorsal  and  ventral  in  position, 
the  ventral  surface  being  that  which  is  nearer  the  isthmus  of  the  ovary.  The 
end  bearing  the  scolex  is  called  the  anterior  end  and  the  opposite,  the  posterior 
end,  despite  differences  of  opinion  as  to  which  is  which.  For  the  sake  of  brevity 
the  words,  "length,"  "depth"  and  "breadth"  (or  "width")  are  used  instead 
of  the  longer  terms,  diameters  in  the  longitudinal,  in  the  dorsoventral  and  in  the 
transverse  directions,  respectively,  excepting  where  the  organ  in  question,  e.g., 
the  transversely  elongated  cirrus-sac  of  the  Triaenophorinae,  is  so  shaped  that 
it  would  be  confusing  to  speak  of  its  obvious  length  as  its  width.  Otherwise 
the  usual  terms  of  orientation  are  employed. 


299]  PSEUDOPHYLLIDEA  FROM  FISHES— COOPER  11 


KEY  TO  FAMILIES,  SUBFAMILIES,  GENERA  AND  SPECIES 

OF  PSEUDOPHYLLIDEA  FROM  FiSHES  DESCRIBED  IN  THIS  PaPER 

1  (14,  15)  Eggs  with  thick  shells  and  opercula.    Opening  of  cirrus  and  vagina 

on  the  same  surface  as  that  of  the  uterus  and  ahead  of  it  or  marginal. 
Family  DIPHYLLOBOTHRIIDAE  Liihe  1910  .  .  2 

2  (11)         Opening  of  cirrus  and  vagina  surficial 3 

3  (8)  Genital  openings  always  on  the  same  surface  of  the  strobila  .  .  4 

4  (7)  Scolex  very  short,  not  distinct  from  the  strobila. 

Subfamily  LIGULINAE  Liihe  1899  .  .  5 

5  (6)  Segmentation  confined  to  the  anterior  end,  or   (in  larvae) 

absent Ligula  Bloch  1782 

Type  and  only  species:  L.  intestinalis  (Linnaeus  1758)  .  .  p.  18 

6  (5)  Segmentation  complete  even  in  the  larval  stages. 

Schistocephalus  Creplin  1829 
Type  and  only  species. 

Schistocephalus  solidus  {O.Y.M^u\[txm())  .  ...  p.  30 

7  (4)  Scolex  (secondar>%  see  below)  similar  in  shape  to  the  first  proglottis; 

no  neck;  segmentation  beginning  immediately  behind  the  scolex, 
but  confined  to  the  anterior  end  of  the  worm. 

Subfamily  HAPLOBOTHRIINAE  Cooper  1917  .  .  p.  42 
Type  and  only  genus  .  .  Haplobothrium  Cooper  1914  .  .  p.  43 
Type  and  only  species:  H.    globulijorme  Cooper  1914  .  .  p.  44 

8  (3)  Genital  openings  of  dijfferent  segments  not  on  the  same  surface,  but 

alternating  irregularly  from  one  surface  to  the  other.    External 
segmentation  little  expressed. 

Subfamily    CYATHOCEPHALINAE    Liihe   1899  .  .  9 

9  (10)         Scolex  an  unpaired,  terminal,  funnel-shaped  organ. 

Cj^thocephalus  Kessler  1868 
Only    American   species:  C.   americanus   Cooper    1917  .  .  p.  53 

10  (9)         Scolex  with  two  almost  spherical  bothria,  the  apertures  of  which 

may  be  separated  or  more  or  less  com^pletely  fused  to  form  a 

single   terminal   opening  ....  Bothrimonus  Duvemoy  1842 

Only    American    species:  B.  intermedius  Cooper    1917  .  .  p.  63 

11  (2)         Opening  of  cirrus  and  vagina  marginal. 

Subfamily    TRIAENOPHORINAE    Luhe  1899    .  .  12 

12  (13)       Scolex  armed  with  four  three-pointed  hooks. 

Triaenophorus  Rudolphi  1793 
Only  larval  forms  of  two  specific  types  present p.  82 

13  (12)       Scolex  sagittate,  or  replaced  by  a  pseudoscolex.     Segmentation 

strongly  expressed,  the  individual  proglottides  very  short  with 

leaf-like  free  lateral  portions FistuKcola  Liihe  1899 

Only  American  species:     F.  plicatus  (Rudolphi  1819)  ...  p.  89 


12  ILLINOIS  BIOLOGICAL  MONOGRAPHS  [300 

14  (1,  15)  Eggs  with  thin  shells  and  no  opercula.    Opening  of  cirrus  and  vagina 

marginal,  that  of  uterus  at  the  same  level  or  slightly  behind  it 
and  ventral.     Segmentation  very  distinct  and  regular. 

Subfamily  MARSIPOMETRINAE  Cooper  1917  .  .  p.  70 
Type  and  only  genus:  Marsipometra  Cooper  1917  .  .  p.  70 
Type  and  only  species:  M.  hastata  (Linton  1898)  .  .  p.  71 

15  (1,  14)  Eggs  with  thin  shells  and  no  opercula.    Opening  of  cirrus  and  vagina 

dorsal  and  behind  the  ventral  uterus-opening,  or  marginal  in 
which  case  sementation  is  not  well  expressed. 

Family  PTYCHOBOTHRIIDAE  Luhe  1902  .  .  16 

16  (27)       Opening  of  cirrus  and  vagina  surficial. 

Subfamily  PTYCHOBOTHRIINAE  Luhe  1899  .  .  17 

17  (26)       Scolex  elongated,  with  prominent   terminal  disc.     Segmentation 

well  developed,  neck  absent. 

Bothriocephalus  Rudolphi  1808  .  .  18 

18  (23)       Scolex  not  pronouncedly  constricted  posteriorly 19 

19  (20)       Uterus-sac  occupies  one-sixth  of  the  transverse  diameter  of  the 

proglottis B.  scorpii  (Miiller  1776)  .  .  p.  96 

20  (19)       Uterus-sac  occupies  one-third  of  the  transverse  diameter  of  the 

proglottis 21 

21  (22)       Scolex  small B,  claviceps    (Goeze  1782)  .  .  p.  114 

22  (21)       Scolex  large,  terminal  disc  deeply  notched  surficially,  sagittate  in 

lateral  view B.  cuspidatus  (Cooper  1917)  .  .  p.  123 

23  (18)       Scolex  constricted  posteriorly 24 

24  (25)       Terminal  disc  deeply  notched  laterally  as  well  as  surficially;  vagina 

pro\ided  with  a  bulbous  sphincter  near  its  opening 

.  .  .  .  B.  manubriformis  (Linton  1889)  .  .  p.  133 

25  (24)       Terminal  disc  rectangular;  no  vaginal    sphincter 

B.  occidmtalis  (Linton  1898)     .  .  p.  149 

26  (17)       Scolex  almost  spherical;  walls  of  each  bothrium  fused  to  form  a 

hollow  organ  of  attachment  with  a  small  anterior  opening 

Clestobothrium  Liihe  1899 
Type  and  only  species:   C.  crassiceps  (Rudolphi  1819)  .  .  p.  154 

27  (16)       Opening  of  cirrus  and  vagina  marginal. 

Subfamily  AMPHICOTYLINAE  Liihe  1902  .  .  28 
Onlygenus  represented Abothrium  van  Beneden  1871. 

28  (29)       Pseudoscolex  in  adult.    Longitudinal  muscles  in  bundles.    Vitelline 

follicles  entirely  within  the  longitudinal  muscles. 

A.  rugosum  (Batsch  1786)  .  .  p.  172 

29  (28)       Scolex  typical,  but  variously  shaped.    Longitudinal  muscles  not 

in  bundles.     Vitelline  follicles  among  the  longitudinal  muscles 
or  outside  of  them A.  crassum  {hloch.  1119)  .  .  p.  186 


301)  PSEUDOPHYLLIDEA  FROM  FISHES— COOPER  13 


Order  PSEUDOPHYLLIDEA  Carus  1863,  nee  Luhe  1910,  e.  p. 

Polyzootic  cestodes  with  mostly  unarmed  scolex  without  rostellum  or  pro- 
boscis formation,  excepting  in  the  Haplobothriinae  where  the  primary  scolex 
is  provided  with  four  protrusible  proboscides  resembling  those  of  the  Try- 
panorhyncha.  Usually  with  two  weakly  developed  sucking  grooves,  which 
in  individual  cases  are  modified  by  the  strong  development  of  their  walls  or  by 
more  or  less  extensive  fusion  of  their  edges,  so  that  they  may  appear  funnel- 
shaped  or  tubular,  which  may  also  unite  with  each  other  more  or  less  com- 
pletely to  form  an  unpaired  terminal  adhesive  organ,  or  become  rudimentary 
or  entirely  absent,  in  which  latter  case  they  are  replaced  by  a  terminal  function- 
al organ  of  attachment.  The  development  of  a  pseudoscolex  takes  place  occa- 
sionally. External  segmentation  more  or  less  pronounced,  only  seldom  com- 
pletely absent.  Genitalia  in  each  segment  usually  single,  seldom  double. 
Their  development  proceeds  from  ahead  backwards  and  does  not  continue 
to  a  degeneration  of  the  reproductive  glands;  but  the  majority  of  the  pro- 
glottides, being  at  the  same  stage  of  development,  bring  their  sexual  products 
to  maturity  at  the  same  time,  so  that  in  all  of  them  new  eggs  are  formed  con- 
tinuously and  all  the  eggs  of  the  whole  animal  are  at  the  same  stage  of  embryon- 
ic development.    A  surficial  opening  of  the  uterus  is  always  present. 

Testes  numerous;  vas  deferens  strongly  coiled,  without  a  true  seminal 
vesicle.  Ovary  near  the  posterior  end  of  the  proglottis,  mostly  median  in 
the  case  of  single  genitalia,  seldom  approaching  the  margin  of  the  strobila 
bearing  the  genital  opening  (that  of  the  cirrus  and  vagina).  Vitelline  follicles 
very  nimierous,  mostly  in  the  cortical,  seldom  in  the  medullary  parenchyma. 
Uterus  a  more  or  less  winding  canal,  the  individual  coils  of  which  converge 
somewhat  towards  the  centre  of  the  proglottis  to  form  the  so-called  rosette; 
but  in  other  forms  it  enlarges  to  form  a  capacious  cavity,  the  uterus-sac,  from 
which  the  duct-like  beginning  of  the  uterus  is  sharply  separated.  Eggs  oper- 
culate  or  non-operculate,  developing  mostly  only  after  being  laid,  but  in  other 
cases  within  the  uterus. 

The  above  diagnosis  of  the  order  is  that  of  Liihe  (1910:11),  minus  the  family 
Caryophyllaeidae  and  partly  emended  to  accommodate  the  subfamily  Haplo- 
bothriinae, in  which  what  is  here  considered  to  be  the  true  (or  primary)  scolex 
is  deprived  of  bothria  but  provided  with  four  eversible  proboscides  quite 
comparable  in  structure  to  those  of  the  order  Trypanorhyncha.  It  is  evident 
that  what  was  formerly  (Cooper,  1914,  1914a)  called  the  scolex  of  Haplo- 
bothrium  cannot  now  be  considered  to  be  a  true  scolex  but  only  the  foremost 
segment  of  the  adult  or  secondary  strobila,  which  is  indicated  by  its  resem- 
blance internally  as  well  as  externally  to  the  segments  immediately  following. 
Whether  or  not  a  pair  of  bothria  were  originally  present  or  are  present  in  the 
very  earUest  stages,  whether  such  bothria  have  become  modified  into  the  pro- 
boscides, or  whether  the  latter  have  developed  from  four  separate  "accessory 


14  ILLINOIS  BIOLOGICAL  MONOGRAPHS  [302 

suckers"  as  believed  by  Pintner  (1880)  to  be  the  case  in  the  Trypanorhyncha, 
must  remain  mere  suggestions  for  the  present.  Furthermore  as  to  the  forma- 
tion of  segments  there  are  in  Haplobothrimn  not  only  conditions  quite  similar 
to  those  in  Bothriocephalus  s.  str.  and  other  genera  in  which  there  is  no  neck, 
segmentation  begmning  immediately  behind  the  scolex,  but  those  reminding 
one  of  the  proliferation  of  scoHces  in  echinococcus.  In  the  former,  as  will  be 
seen  below  where  the  process  is  described  more  in  detail  (p.  102),  a  primary 
segment  divides  up  into  secondary  segments,  these  into  tertiary  segments, 
and  so  on  until  there  may  be  eventually  thirty-two  or  more  genital  segments 
corresponding  to  one  primary  segment  formed  immediately  behind  the  scolex. 
In  Haplobothrium  a  primary  strobila  divides  up  into  primary  segments,  these 
subdivide  into  secondary  segments,  the  definitive  joints  of  the  ordinary  stro- 
bila met  with,  which  in  turn  may  be  subdivided  again  and  evidently  indefinitely 
to  form  new  chains.  The  chief  difference  between  these  two  cases  is  one  of 
degree  of  regularity  in  the  subdivision.  Whereas  in  Bothriocephalus  the  whole 
anterior  region  of  the  worm  is  affected,  evidently  no  division  taking  place 
after  the  rudiments  of  the  reproductive  organs  have  become  separated  from 
the  common  rudiment,  and  the  subsegments  remain  attached  to  one  another, 
in  Haplobothrium  not  only  do  the  primary  segments  separate  as  secondary 
strobilas,  but  in  the  latter  only  a  limited  region  is  involved  in  further  sub- 
division. On  the  other  hand  there  is  somewhat  of  a  resemblance  between 
this  manner  of  subdivision  in  Haplobothrium  and  that  of  the  larval  Echinococ- 
dfer  in  that  the  strobilas  are  developed  from  an  original  "  nurse. "  That  is, 
the  primary  strobila  of  the  former  might  be  looked  upon  as  a  nurse  from  which 
are  developed  segments,  comparable  to  the  daughter-cysts  of  an  echinococcus, 
which  in  turn  produce  (secondary)  scoHces  and  eventually  strobilas.  In  other 
words  there  might  be  recognized  at  first  sight  a  sort  of  alternation  of  generations 
in  the  case  of  Haplobothrium.  But  this  comparison  is  only  a  superficial  one, 
for  as  will  be  shown  below  (under  Haplobothriinae)  the  secondary  scolex  cannot 
be  considered  to  be  a  true  scolex  nor  the  secondary  strobila  a  true  strobila; 
but  the  primary  strobila  with  its  four  proboscides  must  be  regarded  as  such. 
Finally,  this  pecuhar  method  of  segmentation  reminds  one  of  the  asexual  bud- 
ding of  some  of  the  oHgochaete  worms,  particularly  as  regards  the  proliferation 
of  subsegments  in  the  anterior  region  of  the  first  formed  divisions;  but  further 
than  this  the  comparison  can  scarcely  be  carried. 


303]  PSEUDOPHYLLIDEA  FROM  FISHES— COOPER  15 


DIPHYLLOBOTHRIIDAE  Liihe  1910,  char,  emend. 

Polyzootic  Pseudophyllidea  with  unarmed  or  (seldom)  armed  scolex.  Sur- 
ficial  bothria  variously  developed;  they  may  be  modified  to  form  sucking 
tubes,  each  with  an  anterior  and  a  posterior  opening,  thru  the  growth  together 
of  their  free  edges,  or  an  unpaired  terminal  organ  of  attachment  can  serve  as  a 
functional  substitute  for  the  rudimentary  bothria  or  result  from  the  more  or 
less  complete  fusion  of  both  bothria.  The  whole  scolex  may  be  replaced  in 
sexually  mature  specimens  by  a  pseudoscolex;  or  it  may  be  (Haplobothriinae) 
provided  with  four  protrusible  proboscides.  Neck  present  or  absent.  Exter- 
nal segmentation  mostly  present,  seldom  absent.  Genital  organs  numerous, 
mostly  single  in  each  proglottis,  seldom  double.  Cirrus  unarmed  (excepting 
in  Haplobothrium),  with  cleft  cuticula.  Opening  of  cirrus  and  vagina  surficial 
or  marginal;  in  the  first  case  always  on  the  same  surface  as  the  uterus  opening 
and  ahead  of  this  as  well  as  always  in  the  median  line  of  the  genital  complex, 
also  in  the  median  line  of  the  proglottis  in  the  case  of  single  genitalia.  Both 
surfaces  of  the  chain  of  proglottides,  apart  from  the  genital  openings,  similarly 
shaped.  Receptaculum  seminis  formed  by  a  local  enlargement  of  the  vagina 
near  its  inner  end,  which  as  a  rule  is  sharply  separated  from  the  spermiduct 
(terminal  portion  of  the  vagina).  Uterus,  a  long,  more  or  less  winding  canal, 
usually  in  the  form  of  a  rosette,  f6rmed  by  almost  transversely  directed  coils 
crossing  the  median  line.  It  may  be  locally  more  or  less  enlarged,  but  seldom 
forms  an  undivided  uterus-sac  distinct  from  the  uterine  duct,  as  in  the  Ptycho- 
bothriidae.  Eggs  thick  shelled,  with  opercula,  excepting  in  the  Marsipome- 
trinae;  their  formation  is  carried  on  continuously  in  fully-developed  proglot- 
tides; embryonal  development  takes  place  usually  after  liberation,  seldom  in 
the  uterus,  in  which  case,  however,  all  stages  are  found  side  by  side. 

Parasites  of  vertebrates. 

Liihe's  (1910:16)  diagnosis  is  here  emended  to  include  the  new  subfamilies 
Haplobothriinae  and  Marsipometrinae.  In  the  former  not  only  is  the  scolex 
radically  different  from  that  of  any  other  member  of  the  family,  but  the  cirrus 
is  armed  with  minute  spines  and  there  is  a  distinct  uterus-sac,  separate  from 
the  uterine  duct  as  in  the  Ptychobothriidae;  while  in  the  latter  there  is  likewise 
a  uterus-sac  and  the  eggs  are  not  provided  with  opercula.  The  cirrus  of 
Haplobothriurn,  however,  would  seem  to  exclude  the  genus  from  the  family 
Ptychobothriidae  as  well  as  from  the  Diphyllobothriidae,  smce  it  is  not  "un- 
armed, with  cleft  cuticula, "  but  provided  with  minute  yet  distinct  cuticular 
spines  bearing  some  resemblance  to  those  of  the  Acanthophallidae  ( Amphi- 
tretidae),  as  pointed  out  elsewhere  by  the  writer  (1914:3).  But  H.  glohidi- 
fortne  is  otherwise  so  nearly  related  to  Diphyllobothrium  latum  that  it  does  not 
seem  wise  to  remove  it  from  the  family  on  this  account,  especially  since  these 
spines  are  so  minute  and  since  the  evidence  points  to  their  being  probably  of 
little,  if  any,  functional  importance.  The  uterus  on  the  other  hand  is  quite  diff- 


16  ILLINOIS  BIOLOGICAL  MONOGRAPHS  [304 

erent  from  that  of  any  of  the  members  of  this  family  in  that  it  is  distinctly 
divided  into  uterine  duct  and  uterus-sac  as  in  the  Ptychobothriidae.  It  is  true 
that  in  the  genus  Scyphocephalus  one  or  two  of  the  coils  of  the  uterine  rosette 
becomes  much  enlarged  when  the  organ  is  filled  with  eggs,  while  in  Bothridium, 
as  stated  by  Liihe  (1899:49),  "Der  Uterus  bildet  keine  Rosettenform,  lasst 
jedoch  Uteringang  und  Uterus  s.  str.  deutlich  unterscheiden;  letzterer  stellt 
gewissermassen  eine  zweitheilige  Uterushohle  dar,  indem  zwei  hinter  einander 
gelegene  grosse  Hohlraume  durch  einen  kurzen  und  dunnen  Canal  miteinander 
in  Verbindung  stehen."    But  in  neither  case  is  there  a  single  uterus-sac, 
distinct  and  separate  from  the  uterine  duct  or  beginning  of  the  uterus,  but 
only  a  modified  rosette  formation.    Roboz  (1882 :282)  in  describing  the  develop- 
ment of  the  uterus  of  Bothridium  pithonis  said  that:  "In  dieser  Weise  ist  er 
natiirlich  nur  in  jiingeren  Gliedem  entwickelt,  wahrend  er  dort,  wo  die  Be- 
fruchtung  schon  beendet  ist,  in  Folge  der  immer  starkeren  Ansammlung  von 
den  mit  chitinoser  Hiille  imigebener  Eiem  immer  grosser  wird  und  sich  schliess- 
lich  zu  einem  die  ganze  Mittelschicht  ausfiillenden  Sack  ausbreitet. "    It  would 
thus  seem  to  be  comparable  to  that  of  the  Ptychobothriidae  in  that  its  func- 
tional sac  is  developed  by  a  distal  enlargement  of  the  original  duct  which  grad- 
ually encroaches  upon  the  medulla,  but  evidently  there  is  no  separation  of  the 
organ  into  two  distinct  parts  at  any  stage  as  there  is  in  Haplobothrium.    And, 
as  emphasized  elsewhere  by  the  writer,  this  separation  is  present  at  all  stages 
in  the  development  of  the  organ,  which  as  a  matter  of  fact  proceeds  in  quite 
the  same  manner  as  that  of  Bothriocephalus.    In  Marsipometra,  on  the  other 
hand,  even  tho  the  sac  is  formed  in  the  same  way,  it  is  never  very  sharply 
separated  from  the  uterine  duct,  altho  such  appears  to  be  the  case  in  the  adult. 
Reference  to  the  specific  description  below  will  elucidate  this  latter  point. 
Finally  as  regards  the  fact  that  its  eggs  are  not  provided  with  opercula,  Marsi- 
pometra stands  alone.    This  character  would  place  it  at  once  in  the  Ptycho- 
bothriidae, but  it  is  otherwise  so  closely  related  to  the  subfamily  Triaenophor- 
rinae  that  the  family  is  here  emended  to  accommodate  it.    Thus  it  is  seen  that 
on  account  of  these  two  isolated  genera  the  two  families  Diphyllobothriidae 
and  Ptychobothriidae  are  much  more  closely  related  than  was  formerly  thought 
to  be  the  case. 

LIGULINAE  Liihe  1899 

Scolex  unarmed,  very  short,  almost  triangular,  with  anterior  end,  more  or 
less  drawn  out  into  a  point  according  to  the  state  of  contraction,  passing  directly 
into  the  chain  of  proglottides  or  the  similarly  shaped  unjoitited  body;  surficial 
bothria  small,  weakly  developed.  Neck  absent.  Formation  of  proglottides 
complete,  confined  to  the  anterior  end  or  (in  young  animals)  absent.  Posterior 
end  rounded.  Nervous  system  distinguished  by  a  large  number  of  plexus- 
forming  longitudinal  nerves  near  both  chief  strands.  Genital  organs  in  sexually 
mature  individuals  completely  developed  close  behind  the  scolex.  Genital 
openings  surficial,  ventral,  lying  behind  or  near  one  another  and  near  the 
median  line.    Testes  in  a  simple  dorsal  layer  in  the  lateral  fields  of  the  medul- 


305]  PSEUDOPHYLLIDEA  FROM  FISHES— COOPER  17 

lary  parenchyma,  for  the  most  part  lateral  to  the  nerve  strands.  Ovary  and 
sheU-gland  median,  the  former  ventral,  the  latter  dorsal.  Vitelline  follicles 
in  the  form  of  a  mantle  in  the  cortical  parenchyma.  Vas  deferens  enlarged  to 
a  muscular  bulb  before  entering  the  cirrus-sac.  Receptaculum  seminis  large, 
sharply  separated  from  the  short  and  narrow  spermiduct. 

Sexually  mature  in  the  intestines  of  water  birds;  present  as  larvae  in  the 
body-cavities  of  teleosts  where  they  grow  quite  large  and  develop  the  rudiments 
of  the  reproductive  organs;  occasionally  also  observed  free  in  the  water  which 
they  reach  by  the  rupture  of  the  greatly  distended  body-wall  of  the  intermediate 
host. 

Type  genus:  Ligula  Bloch 

In  the  above  diagnosis  of  the  subfamily  by  Liihe  (1910:17)  the  statement 
that  the  testes  are  *'  in  einfacher  dorsaler  Schicht  den  Seitenfeldem  des  Mark- 
parenchyms  grossentheils  lateralwarts  von  den  Markstrangen "  is  somewhat 
confusing,  for  it  is  strictly  correct  only  when  the  whole  number  of  testes  is 
taken  into  consideration.  In  transections  of  both  Ligula  and  Schistocephalus 
the  nerve  strand  was  actually  found  to  be  more  than  half  way  from  the  median 
line  to  the  margin  of  the  medulla,  but  the  testes  were  much  more  closely 
crowded  in  the  lateral  portion  of  the  field,  hence  making  their  total  number 
there  more  than  in  the  median  field.  But  the  differences  between  the  two  fields 
on  each  side  in  this  regard  were  seen  in  confirmatory  frontal  sections  to  be 
much  greater  in  Ligula  than  in  Schistocephalus. 

LIGULA  Bloch  1782 


Taenia  (part.) 

Auctorum 

Fasciola  (part.) 

Linnaeus 

1758 

Fasciola  (part.) 

Linnaeus 

1767 

Ligula 

Bloch 

1782 

Fasciola  (part.) 

Goeze 

1782 

Bothriocephalus  (part.) 

Nitzsch 

1824 

Ligula 

Creplin 

1839 

Dibothriura  (part.) 

Donnadieu 

1877 

Bothria  as  well  as  external  segmentation  completely  absent  from  the  larvae, 
both  develop  simultaneously  with  the  maturation  of  the  sex-organs  in  the 
definitive  host,  where  the  external  segmentation  which  does  not  correspond 
with  the  internal  is  confined  to  the  anterior  end.  Longitudinal  and  transverse 
muscles  irregularly  interwoven  in  the  anterior  end,  posteriorly  separated  into 
an  inner  transverse  and  an  outer  longitudinal  layer. 

Type  (and  only)  species:  Ligula  intestinalis  (L.). 


18 


ILUNOIS  BIOLOGICAL  MONOGRAPHS 


(306 


LIGULA  INTESTINALIS  (Linnaeus 
[Figs.  1,  2,  78,  98] 


1758) 


LARVAL  stage: 

1713 

Taenia 

1740 

Taenia  capitata 

1758 

Fasciola  inteslinalis 

1767 

Fascida  intestinalis 

1781 

Taenia  cingulum 

1782 

Ligula  piscium 

1782 

Fascida  abdominalis 

1790 

Ligula  abdominalis 

1790 

Ligula  a.  alburni 

1790 

Ligula  a.  branuu 

1790 

Ligula  a.  carassii 

1790 

Ligula  a.  cobitidis 

1790 

Ligula  a.  cyprinorum 

1790 

Ligula  a.  gobionis 

1790 

Ligtda  a.  leuscisci 

1790 

Ligula  a.  trincae 

1790 

Ligula  a.  vimbae 

1790 

'Ligula  petrotnyzontis 

1793 

Ligula  salvelini 

1802 

Ligula  simplicissima 

1803 

Ligula  alburni 

1803 

Ligula  bramae 

1803 

Ligula  carassii 

1803 

Ligula  cobiiidis 

1803 

Liguli  colymbi 

1803 

Ligula  gobionis 

1803 

Ligula  Icucisci 

1803 

Ligula  trincae 

1803 

Ligula  vimbae 

1810 

Ligula  acuminata 

1810 

Ligula  cingulum 

1810 

Ligula  constringens 

1810 

Ligula  coniortrix 

1819 

Ligula  simplicissima 

1819 

Ligula  crispa 

1819 

Ligula  edulis 

1839 

Ligula  simplicissima 

1839 

Ligtda  monogramma 

1839 

Ligula  digramma 

1853 

Ligula  simplicissima 

1855 

Ligula  monogramma 

1861 

Ligula  monogramma 

1891 

Ligtda  catostomi 

1896 

Ligula  monogramma 

1898 

Dibothrium  ligula 

1899 

Ligula  abdominalis 

ADULT  stage: 

1782 

Ligula  avium 

1782        Fascida  intestinalis 


Geoffrey 

1713  ; 

:50 

Frisch 

1740 

:121 

Linnaeus 

1758  : 

:649 

Linnaeus 

1767 

:1078 

PaUas 

1781 

:95 

Bloch 

1782  : 

:2 

Goeze 

1782 

:187 

Gmelin 

1790 

:3a43 

Gmelin 

1790 

:3043 

Gmelin 

1790 

:3043 

Gmelin 

1790 

:3043 

Gmelin 

1790 

:3043 

Gmelin 

1790 

:3043 

Gmelin 

1790 

:3043 

Gmelin 

1790 

:3043 

Gmelin 

1790 

:3043 

Gmelin 

1790 

:3043 

Schrank 

1790 

:119 

Schrank 

1793 

:143 

Rudolphi 

1802 

:99 

Zeder 

1803 

:266 

Zeder 

1803 

:263 

Zeder 

1803 

:  262-3 

Zeder 

1803 

:266 

Zeder 

1803 

:266 

Zeder 

1803 

:265 

2:eder 

1803 

:265 

Zeder 

1803 

:265 

Zeder 

1803 

:295 

Rudolphi 

1810 

:24 

Rudolphi 

1810 

:  20-22,  31 

Rudolphi 

1810 

: 22-24 

Rudolphi 

1810 

:  18-19 

Rudolphi 

1819 

:134 

Rudolphi 

1819 

:  134-135 

Briganti 

1819 

:209 

Creplin 

1839 

:295 

Creplin 

1839 

:296 

Creplin 

1839 

:296 

Baird 

1853 

:95 

Leidy 

1855 

:444 

Van  Beneden 

1861 

:139 

Linton 

1891 

:66 

Zschokke 

1896 

:  773,  774,  775 

Linton 

1898 

:438 

Luhe 

1899 

:S2 

Bloch 

1782 

:4 

Goeze 

1782 

:183 

3071 

PSEUDOPHYLLIDEA  FROM  FISHES- 

■COOPER 

ADtTLT  STAGE 

1790 

Ligida  iniestinalis 

Gmelin 

1790 

:3042 

1802 

Ligiila  sitnplicissima 

Rudolphi 

1802 

:99 

1803 

Ligida  colymbi 

Zeder 

1803 

:266 

1810 

Ligula  uniserialis 

Rudolphi 

1810 

:12 

1810 

Ligida  allernans 

Rudolphi 

1810 

:13 

1810 

Ligula  interrupta 

Rudolphi 

1810 

:15 

1810 

Ligula  sparsa 

Rudolphi 

1810 

:16 

1819 

Ligula  uniserialis 

Rudolphi 

1819 

:132 

1819 

Ligula  alternans 

Rudolphi 

1819 

:133 

1819 

Ligula  interrupta 

Rudolphi 

1819 

-.133 

1819 

Ligida  sparsa 

Rudolphi 

1819 

:133 

1824 

Bothriocephalus  semiligtda 

Nitzsch 

1824 

:98 

1839 

Ligula  uniserialis 

Creplin 

1839 

:296 

1839 

Ligula  interrupta 

Creplin 

1839 

:296 

1844 

Ligida  sparsa 

Bellingham 

1844 

:165 

1845 

Ligula  uniserialis 

Dujardin 

1845 

:628 

1845 

Ligida  alternans. 

Dujardin 

1845 

:629 

1845 

Ligida  interrupta 

Dujardin 

1845 

-.629 

1845 

Ligida  sparsa. 

Dujardin 

1845 

:629 

?1845 

Ligida  nodosa 

Dujardin 

1845 

:629 

1850 

Ligula  monogramma 

Diesing 

1850 

:579 

1850 

Ligida  digramma 

Diesing 

1850 

:580 

1853 

Ligula  interrupta 

Baird 

1853 

:96 

1853 

Ligida  sparsa 

Baird 

1853 

:96 

1854 

Ligida  monogramma 

Diesing 

1854  ; 

:19 

1854 

■  Ligula  digramma 

Diesing 

1854  : 

:18 

?1856 

Ligula  reptans 

Leidy 

1856  ; 

:46 

1863 

Ligula  monogramma 

Diesing 

.  1863  : 

:230 

1863 

Ligida  digramma 

Diesing 

1863  : 

:231 

1870 

Ligida  monogramma 

Willemoes-Suhm 

1870  : 

;94 

1877 

Dibothrium  ligida 

Donnadieu 

1877  : 

:495 

1881 

Ligida  simplicissima 

Moniez 

1881  ; 

;  37,  81 

1882 

Ligida  simplicissima 

Kiessling 

1882 

1884 

Dibothrium  ligida 

Zschokke            » 

1884  : 

26 

1885 

Ligida  simplicissima 

Schauinsland 

1885  ; 

:550 

1888 

Ligula  simplicissima 

Niemiec 

1888  ; 

;2 

1893 

Ligula  monogramma 

Olsson 

1893  : 

15 

1894 

Ligida  simplicissima 

Stiles  and  Hassall 

1894  ; 

331 

1895 

Ligula  monogramma 

Zernecke 

1895  : 

93 

1895 

Ligida  digramma 

Zeraecke 

1895  : 

93 

1896 

Ligula  simplicissima 

Zschokke 

1896  ; 

; 773,  774,  775 

1898 

Ligula  digramma 

Cohn 

1898  ; 

;134 

1898 

Ligula  uniserialis 

Luhe 

1898  : 

286 

1898 

Ligula  uniserialis 

Muehling 

1898  ; 

;32 

1898 

Ligula  monogramma 

Stossich 

1898  ; 

;118 

1899 

Ligida  intestinalis 

Luhe 

1899  ; 

;52 

1900 

Ligula  avium 

Braun 

1900  : 

:1687 

1900 

Ligida  uniserialis 

Wolffhuegel 

1900; 

:63 

1901 

Ligida  intestinalis 

Linstow 

1901a 

1902 

Ligida  monogramma 

Parona 

1902  ; 

;7 

1902 

Ligula  intestinalis 

Schneider 

1902a 

:13 

1903 

Ligida  intestinalis 

Linstow 

1903  ; 

;20 

1910 

Ligula  intestinalis 

Liihe 

1910: 

18 

19 


20  ILLINOIS  BIOLOGICAL  MONOGRAPHS  [308 

Specific  diagnosis :  With  the  characters  of  the  genus.  Large  worms  from  1 00 
to  lOOOnmi.  in  length  by  5  to  15mm.  in  breadth.  Anterior  end  rounded,  pro- 
truding ;  bothria  faint.  Strobila  greatly  elongate,  depressed,  maximum  breadth 
anterior  to  the  middle,  gradually  tapering  to  the  posterior  end.  Body  crossed 
by  irregular  ridges  and  furrows,  and  wavy  at  the  margins  in  the  adult,  with 
35  to  40  external  segments  anteriorly.  Deep  median  groove  on  each  surface 
in  the  larva,  two  very  shallow  parallel  grooves  near  the  median  line  on  the 
dorsal  surface  in  the  adult. 

Cuticula  5  to  20/i  in  thickness,  subcuticula  50  to  llO^u.  Nerve  strands  50  to 
100/x  in  diameter.  Excretory  vessels  numerous  in  three  layers,  one  close 
beneath,  among  or  just  outside  of  the  vitelline  glands  (cortical),  another  among 
the  main  body  muscles,  and  a  third  in  the  medulla. 

Genitalia  from  0.05  to  0,20mm.  apart.  Genital  cloaca  a  narrow  transverse 
sht,  0.18  to  0.20  by  0.02  to  0.03mm.  into  which  open  separately  the  cirrus, 
uterus,  and  vagina,  the  latter  constantly  between  the  other  two  which  alternate 
irregularly  from  side  to  side. 

Testes  interrupted  only  medially,  20  to  40  in  transection,  115  to  145  by 
80  to  85  by  45  to  55/x  in  dimensions.  Vas  deferens  up  to  35At  in  diameter,  loosely 
coiled  above  the  cirrus-sac.  Seminal  vesicle  small,  close  above  the  latter, 
65  to  100  by  40  to  90/x.  Cirrus-sac  somewhat  lateral,  ovoid,  with  thin  walls, 
185  to  215  by  130  to  160  by  130  to  145/x.  Cirrus  proper  within  cirrus-sac,  long 
and  coiled,  25/*  in  diameter. 

Vagina  15  to  30/1  in  diameter,  receptaculum  seminis  75  to  90/i.  Spermi- 
duct  short,  20  to  25  by  6  to  12/i.  Ovary  0.5  to  1.5  mm.  in  diameter;  wing  great- 
ly depressed,  isthmus  prominent  and  not  in  the  median  line  but  alternating 
irregularly  from  side  to  side  opposite  the  cirrus-sac;  ova  in  same  12  to  15/x  in 
diameter.  Oocapt  18  to  20/i  in  diameter,  oviduct  15  to  20/i.  Vitelline  reservoir 
ellipsoidal  in  shape,  sharply  separated  from  the  duct  on  either  side,  40 
by  30/i.  Vitelline  follicles  irregular  in  shape,  50  to  70  by  15  to  30/t,  in  a  layer 
close  beneath  the  subcuticula  and  broken  only  ventrally.  Shell-gland  composed 
of  much  elongated  cells  with  enlarged  bodies  and  narrow  necks  connecting  with 
the  oviduct  for  30/i  of  its  length.  Uterus  a  mass  of  coils  in  the  median  line, 
0.4  to  0.6mm.  in  diameter,  that  of  the  tube  being  30  to  60/c. 

Eggs,  50  to  65  by  30  to  42/t. 

Habitat:  As  larvae  in  the  body-cavities  of  teleosts;  adults  in  the  intestines 
of  wading  and  diving  birds. 


309] 


PSEUDOPHYLLIDEA  FROM  FISHES— COOPER 


21 


HOST 


COLLECTOR 


AUTHORITY 


Larval  stage: 


Leuciscus  rutUis 
Abratnis  bratna 
Cyprinus  alburnus 
A  spins  rapax 

Gobio  vulgaris 
Carrassius  gibelio 
Petromyzon  branchialis 
Cobitis  taenia 
Salmo  salvelinus 
Coregonus  wartmanni 
Siluris  glanis 
Esox  Iticius 
Perca  fluviatilis 


Lucioperca  sandra 
fPhoca  vittdina 
Morrhua  atnericana 
Squalius  cephalus 
Alburnus  lucidus 

Atherina  mocho 

Blicca  bjorkna 
Catostomus  ardens 

Chondrostoma  nasus 
Catostomus  latipinnis 

Osmerus  mordax 

Hybognathus  nuchalis 
Notropis  cornutus 


Schizopygopsis  kozlovi 

Nemachilus  strauchi 

Tinea  vulgaris 

Gobio  gobio 

Scardinius  erythropkthaJ- 

mus 
Ameiurus  sp. 

Alosa  ohiensis 
Perca  fluviatilis 


East  Prussia 
Berlin 
Iljmen-See, 
Novogorod 


Sweden 
L.  Storsjon, 
Jemtland,  and 
Bonan,  Sweden 


Berlin 


Langviken  Bay, 

Finland 

Cagliari 


Yellowstone  Nat. 

Park 

Basel 

Gila  R.  and 

Salt  R.,  Arizona 

Potomac  R., 

Hagerstown,  Md. 


Fourth  Lake, 

Adirondacks, 

New  York 

Tan-la-Gebirge, 

Tibet 

Issyk-kul-See, 

Bai  Karasu 


Charlevoix, 

Keokuk,  Iowa 
Walnut  Lake, 
Michigan 


Zschokke 

Schauinsland 

Goeze 

Varpachovskij 

Rudolphi 

Rudolphi 

Schrank 

Bloch 

Schrank 

Schrank 

Mus.  Vienna 

Olsson 


Olsson 
Mus.  Vienna 
Rudolphi 
Schafirt 
Zschokke 

Levander 
Parona  and 
Mazza 
Linstow 

D.  S.  Jordan 

Zschokke 

E.  Pahner 

C.  E.  Ridenour 


F.  Mather 
Przevalskij 
P.  Schmidt 


H.  B.  Ward 
H.  B.  W^ard 
H.  B.  Ward 


Zschokke  1884 
Muehling  1898 
Goeze  1782 


26 
33 
187 


Linstow 

Diesing 

Diesing 

Rudolphi 

Rudolphi 

Diesing 

Diesing 

Diesing 

Olsson 


Olsson 

Diesing 

Rudolphi 

Leidy 

Zschokke 


1903  :  285 
1850  :  581 
1850  :  581 
1810  :  24 
1819  :  134 
1850  :  581 
1850  :  581 
1850  :  581 
1893  :  15 


1893  :  15 
1850  :  581 
1819  :  135 
1855  :  444 
1884  :  26 


Schneider  1902a  :  13 
Parona  and 

Mazza  1900  :  233 

Linstow  1901a  :  629 

Linton  1891  :  65 

Zschokke  1896  :  775 

Linton  189S  :  438 

Linton  1898  :  438 

Linton  1898  :  438 


Linton 

Linstow 

Linstow 

Neveu- 

Lemaire 

Liihe 

Liihe 


1898  :  438 
1903  :  285 
1903  :  285 

1909  :  88 

1910  :  19 
1910  :  19 


Cooper  (the  present 
paper) 


22 


ILLINOIS  BIOLOGICAL  MONOGRAPHS 


[310 


HOST 

LOCALITY 

COLLECTOR 

AUTHORITY 

Perca  flavescens 

Go-Home  Bay, 
Muskoka  District, 

Ontario 

A.  R.  Cooper 

>> 

Catostomus  commersonii 

Walnut  Lake, 

Michigan 

H.  B.  Ward 

)> 

Caiostomus  commersonii 

Douglas  Lake, 

Michigan 

H.  R.  Hill 

»> 

Catostomus  commersonii 

Douglas  Lake, 

commersonii 

Michigan 

A.  R.  Cooper 

i» 

Notropis  cornutus 

Go-Home  Bay 

A.  R.  Cooper 

>> 

Notropis  cayuga 

Douglas  Lake, 

Michigan 

H.  R.HiU 

»> 

Notropis  hudsonius 

Douglas  Lake, 

Michigan 

G.  R.  LaRue 

>> 

Microptents  dolomieu 

Go-Home  Bay 

A.  R.  Cooper 

»> 

fe       Ambloplites  rupestris 

Go-Home  Bay 

A.  R.  Cooper 

II 

Ambloplites  rupestris 

Douglas  T^ke, 

Michigan 

G.  R.  LaRue 

»» 

Gasterosteus  bispinosus 

Chamcook  Lake, 

atkinsii 

New  Brunswick 

A.  R.  Cooper 

>f 

Ambystoma  sp. 

Sand  HiUs, 

Nebraska 

G.  R.  LaRue 

» 

Amby stoma  tigrinum 

Cherry  Co., 
Nebraska 

G.  R.  LaRue 

>> 

Free  on  shore 

Douglas  Lake, 

H.  R.  Hill 

1) 

Michigan 

G.  R.  LaRue 
A.  R.  Cooper 

>> 
>> 

Adult  stage: 

Falco  albicilla 

Greiphswald 

Creplin 

CrepUn 

1839  :  296 

Ciconia  alba 

— 

Hildebrandt 

Diesing 

1850  :  580 

Ardea  nycticorax 

M.  C.  V. 

Diesing 

1850  :  580 

Colymbtis  arcticus 

Mehhs 
Parona 

Diesing 
Parona 

1850  :  581 

Podiceps  auritus 

Varese 

1902  :  7 

Anas  boschas  fera 

Mus.  Vienna 

Rudolphi 

1819  :  134 

Larus  argentatus 

Kainsk,  Enissej 

Middendorff 

Linstow 

1903  :  20 

Sterna  hirundo 

Mus.  Vienna 
Schneider 

Rudolphi 
Schneider 

1819  :  133 

Mergus  serrator 

Gulf  of  Finland 

1902a  :  13 

Nycticorax  nycticorax 

Liihe 

1910  :  18 

Graculus  carbo 

M.  Siebold, 
Coll.  Brit. 

Museum 

Baird 

1853 

96 

Ftdigtda  clangula 

Jemtland 

Olsson 

Olsson 

1893 

15 

Xema  minutum 

Trieste 

Stossich 

Stossich 

1898 

118 

Urinator  arcticus 

Liihe 
Liihe 
Liihe 
Liihe 

1900 
1900 
1900 
1910 

18 

Rissa  tridactyla 

18 

Stercorarius  parasitica 

18 

Eydrochelidon  nigra 

18 

Herodias  alba 

Liihe 
Liihe 

1910 
1910 

18 

Haliaetus  albicilla 

18 

311] 


PSEUDOPHYLLIDEA  FROM  FISHES— COOPER 


23 


HOST 

LOCALITY 

COLLECTOR 

AUTHORITY 

Aquila  chrysaetus 
Corvus  comix 

Luhe             1910  :  18 

» 

Liihe            1910  :  18 

Podilymbus  podiceps 

Merganser  sp. 
Colymbus  hoelbeelli 
Mergus  merganser 

H.  B.  Ward 

H.  B.  Ward 
H.  B.  Ward 
G.  R.  LaRue 

Cooper  (the  present 
paper) 

Urbana,  Illinois 

Douglas  Lake, 
Michigan 

>> 

The  species  has  also  been  reported  in  Europe  and  Asia  from  the  following 
additional  hosts: 

Larval  stages:  Abramis  bjorkna,  A.  blicca,  A.  vimba,  Alburnus  alburnus, 
Ammocoetes  branchialis,  A  spins  alburnus, Carassius  car  assius,  C.  vulgar  is,  Cobitis 
aculeata,  Cyprinus  blicca,  C.  brama,  C.  carassius,  C.  gobio,  C.  lacusiris,  C.  leucis- 
cus,  C.  tinea,  Gobio  fluviatilis,  Leuciscus  erythrophthalmus,  L.  leuciscus,  L, 
phoxinus,  L.  pulchellus,  L.  vulgaris,  Lucioperca  lucioperca,  Squalius  turcicus. 

Adult  stages:  Ardea  alba,  A.  ciconia,  A.  egretta,  Ciconia  ciconia,  C.  nigra, 
Colymbus  auritus,  C.  cristatus,  C.  griseigena,  C.  rubricollis,  C.  septentrionalis, 
C.  subcristatus,  Falco  chrysaetos,  F.  fulvus,  Larus  canus,  L.  ntelanocephalus,  L. 
parasiticus,  L.  pelecanus  carbonis,  L.  pygmaei,  L.  ridibundus,  L.  tridactylus, 
Mergus  albellus,  M.  merganser,  M.  minutus,  Podiceps  minor,  P.  nigricollis, 
P.  rubricollis.  Sterna  nigra,  Totanus  chloropus,  Urinator  stellatus,  Xema  ridi- 
undum. 


As  indicated  in  the  above  synonymy,  the  greatest  confusion  has  existed 
in  connection  with  this  species  from  the  time  of  Linnaeus  to  that  of  Liihe 
(1899),  all  of  the  older  writers  recognizing  at  least  two  species,  the  larval  and 
the  adult,  and  many,  several  species  under  each  of  these.  Rudolphi  (1810), 
for  instance,  accepted  four  species  of  the  former,  "ovariis  occultatis,"  and 
the  same  number  of  the  latter,  parasitic  in  the  intestines  of  birds,  "ovariis 
distinctis."  In  his  Entozoorum  Synopsis  (1819)  he  reduced  the  number  of 
larval  species  to  two,  but  retained  the  same  four  adult  forms  as  before.  The 
next  important  move  in  a  systematic  direction  was  by  Creplin  (1839)  who 
divided  Rudolphi's  L.  simplicissima  into  two  larval  species,  viz.,  L.  monogram- 
ma  and  L.  digramma,  corresponding  respectively  to  the  previously  known  L. 
uniserialis  and  L.  interrupta  (or  alternans),  which  plan  was  followed  by  Diesing 
(1850,  1854,  and  1863)  while  Dujardin  (1845)  and  Baird  (1853)  followed  Ru- 
dolphi. Diesing  (1850:581)  erected  a  third  species,  L.  reptans,  to  accommodate 
numerous  forms  found  encysted  in  the  muscles  and  connective  tissues  of  am- 
phibians, reptiles,  birds  and  mammals;  but  as  pointed  out  by  Janicki  (1906:519) 
several  larval  species  were  probably  included  under  this  heading.  Those 
from  avian  hosts  are  not  given  above  since  they  were  foimd  only  among  the 


24  ILUNOIS  BIOLOGICAL  MONOGRAPHS  [312 

muscles  and  under  the  skin,  where  L.  intestinalis  has  never  been  found  in  birds, 
so  far  as  the  available  records  indicate.  Liihe  (1910:18)  did  not  include  them 
in  his  list  of  hosts  for  the  adult  stage  of  the  species. 

Next  in  order  of  importance  came  Donnadieu's  (1877)  classical  experiments 
in  which,  after  completely  reviewing  the  Uterature  up  to  date,  he  conclusively 
proved  that  the  form  found  in  the  body  cavities  of  various  bony  fishes  is  the 
larval  stage  of  that  present  in  the  intestines  of  birds.  As  a  result  of  his  work 
he  combined  the  two  forms  under  a  new  name,  Dibothriiim  ligula,  confusing 
at  the  same  time  Schistocephalus  solidus  with  Ligula  intestinalis.  The  life- 
history  of  the  species  was  later  studied  by  Riehm  (1882)  by  feeding  methods. 
Moniez  (1881:37,  81)  was  the  first  writer  to  study  the  histology  of  the  species, 
while  Kiessling  (1882)  gave  the  first  description  of  its  general  anatomy.  As 
emphasized,  however,  by  Linstow  (1901a),  Kiessling's  work  is  not  very 
specific,  since  he  ahnost  constantly  disposed  of  L.  intestinalis  by  saying  that 
in  it  conditions  were  the  same  as  in  Schistocephalus  solidus.  While,  apart 
from  Donnadieu  and  the  earUer  writers,  Willemoes-Suhm  (1870:94)  was  the 
first  to  study  the  development  of  the  embryo  with  attention  to  detail,  Schauins- 
land  (1885:550)  enlarged  upon  his  observations  and  gave  a  more  or  less  com- 
plete description  of  the  process  up  to  the  time  of  the  escape  of  the  ciliated  larva. 
Niemiec  (1888:2)  described  the  nervous  system,  and  Cohn  (1898:134)  pointed 
out  its  resemblance  to  Sch.  solidus  in  this  regard.  Zemecke  (1895)  in  the  mean- 
time dealt  in  his  well  known  work  on  the  finer  structure  of  cestodes  with  the 
parenchyma  and  the  nervous  and  muscular  systems  in  particular;  since  then 
little  has  been  done  in  that  connection.  The  question  of  segmentation  was 
studied  by  Liihe  (1898).  Later  the  same  writer  (1899:52)  placed  the  species 
in  his  first  classification,  stating  as  his  behef  that  there  is  only  one  species  of 
Ligula,  viz.,  L.  intestinalis  (L).  The  latter  conclusion  was  also  arrived  at  by 
Linstow  (1901a:628),  altho  he  attributed  the  specific  name  to  Goeze;  while  in 
his  latest  classification  Luhe  (1910)  maintained  the  same  view. 

Consequently,  taking  for  granted  in  the  absence  of  European  material  for 
comparison  that  the  latter  has  been  established  as  a  fact  for  the  European 
forms,  the  problem  is  to  determine  whether  the  same  species  occurs  here  in 
America.  So  far  as  the  majority  of  specific  characters  are  concerned,  one  must 
rely  on  the  descriptions  of  Kiessling  and  Linstow  (1901a)  who  seem  to  have 
been  the  only  writers  to  attend  to  the  details  of  the  reproductive  system, — 
and  as  metioned  above,  Kiessling's  is  quite  inadequate  in  this  connection. 
The  only  American  reports  of  the  species  are  of  larval  forms:  L.  monogramma 
by  Leidy  (1855:444)  and  Dibothrium  ligula  by  Linton  (1898:438),  the  former 
having  also  listed  (1856:46)  the  doubtful  L.  reptans. 

Liihe  (1910:18)  gave  the  dimesionsof  the  species  as  100  to  400  mm.  (occasion- 
ally 1  meter)  in  length  by  from  5  to  15mm.  in  breadth,  not  distinguishing  how- 
ever, between  the  larva  and  the  adult  in  this  regard.  Linstow  (1901:629) 
reported  a  larva  from  Blicca  bjorkna  200mm.  long,  9  broad  and  3.5  thick,  adults 
from  Podiceps  cristatus  and  Merganser  merganser  160mm.  long,  4  broad  and  1.5 
thick.     Concerning  these  differences  he  said  that:  "  Wenn  man  die  Geschlechts- 


313]  PSEUDOPHYLLIDEA  FROM  PISHES— COOPER  25 

form  aus  Vogeln  oft  kleiner  findet  als  die  Larve  aus  Fischen,  so  mag  das  seinen 
Grund  datin  haben,  dass  die  letztere  sich  in  der  Grosse  ihren  Wirth  anpasst; 
die  grossen  Larven  in  grossen  Fischen  konnen  aber  nicht  von  kleineren  Vogeln 
verschlungen  werden."  The  largest  larval  specimen  at  hand  was  one  from 
Catostomus  commersonii  which  measured  425mm.  in  length  by  15  in  maximum 
breadth,  but  the  largest  adult  from  Merganser  merganser  was  only  217  by  6mm. 
In  the  larva  the  anterior  end  is  somewhat  bluntly  rounded  (Fig,  1),  the  bothria 
being  \nsible  as  very  short  grooves  passing  over  the  tip,  while  in  the  adult  they 
are  more  elongated  and  distinct,  the  end  of  the  strobila  being  somewhat  pro- 
truded as  shown  in  figure  2 .  On  each  surface  of  the  larva  there  is  a  deep,  median, 
longitudinal  furrow,  which  however,  becomes  obliterated  in  the  adult,  except- 
ing anteriorly,  by  the  growth  of  the  reproductive  organs,  the  ducts  of  which 
are  confined  to  the  median  line  of  the  strobila.  When  these  are  developed 
the  strobila  is  characterized  dorsally  by  a  low  median  ridge  bounded  on  each 
side  by  a  quite  shallow  groove,  and  ventrally  by  a  greater  thickening  of  the 
median  line,  not  separated,  however,  by  any  grooves  from  the  lateral  regions. 
The  whole  strobUa  gradually  tapers  from  a  short  distance  behind  the  anterior 
end,  where  the  maximum  breadth  is  located,  to  the  posterior  end.  Whereas 
in  the  larva  it  is  quite  thick,  in  the  adult  it  is  thin  and  leaf-like,  the  margins 
usually  appearing  wavy  in  alcoholic  specimens,  especially  posteriorly.  A 
pseudosegmentation  is  present  in  the  anterior  end  of  the  strobila,  but  as  has 
been  known,  especially  since  Liihe  (1898)  emphasized  the  fact,  this  division 
of  the  strobila  into  segments  does  not  correspond  with  the  internal  division 
into  true  proglottides.  Gemmill  (1909:11)  counted  about  50  of  them  in  the 
anterior  third  of  the  worm,  the  writer  38  or  39  for  a  distance  of  13mm.  from 
the  tip  of  one  adult  specimen  (Fig.  2)  and  36  for  10mm.  in  another.  They 
vary  considerably  in  length  and  are  often  incomplete  medially.  From  the 
anterior  region  showing  external  segmentation  to  the  posterior  end  both  larvae 
and  adults,  but  particularly  the  latter,  are  crossed  by  very  numerous  irregular 
grooves,  which  give  the  worm  its  characteristic  appearance  apart  from  the 
general  shape  as  contrasted,  for  instance,  with  the  closely  related  Schistocepha- 
lus  solidus.  The  smallest  larva  met  with  was  one  from  a  small  specimen  of 
Micropterns  dolomieu,  47mm.  in  length.  It  gave  the  following  measurements: 
length,  4.9mm.;  maximum  width,  0.54mm. ;  width  one-third  the  length  from 
the  anterior  end,  0.54mm.,  two-thirds,  0.37mm.;  length  of  bothrial  groove 
about  0.07mm. 

The  cuticula  was  found  to  have  a  thickness  of  from  5  to  15m,  compared  with 
16  to  18/i  by  Kiessling  and  2.1  (!)  by  Linstow.  It  appears  homogeneous  in 
sections  rather  than  divisible  into  the  three  layers  described  by  the  former, 
with  some  tendency,  however,  for  the  outer  one-quarter  to  one-sixth  to  take 
the  stain  much  less  than  the  remainder  of  the  tissue,  which  outer  clearer  area 
is  often  bounded  by  a  very  delicate  pseudociliated  layer.  There  is  a  good  deal 
of  variation  not  only  in  the  thickness  of  the  cuticula  but  also  in  its  structure; 
and  these  remarks  apply  to  the  larva  as  well  as  to  the  adult.  The  subcuticula 
varies  from  50  to  110^  in  thickness,  or  33  to  49/z  according  to  Kiessling  and 


26  ILLINOIS  BIOLOGICAL  MONOGRAPHS  [314 

114/i  to  Linstow.  Calcareous  bodies  in  the  characteristically  fine  parenchyma, 
described  by  Moniez  and  Zernecke,  and  given  dimensions  of  13  by  7.8/i  by 
Linstow,  were  observed  in  the  largest  living  specimens  from  the  body-cavity 
of  Catostomus  commersonii  commersonii  to  be  extremely  numerous,  spherical  to 
ellipsoidal  in  shape  and  to  measure  from  14  to  IQjU  in  length  by  12  to  17  in 
breadth. 

The  musculature  has  been  well  described  histologically  by  Zernecke  (1895); 
while  KiessUng  spoke  rather  briefly  of  its  arrangement  in  the  late  larva.  Later 
Liihe  dealt  with  the  system  in  general  (1897a  and  1898)  and  its  relation  to  the 
nervous  system  (1896),  and  Linstow  (1901a),  gave  a  concise  account  of  its 
arrangement. 

The  chief  nerve  strands  are  situated  in  transections  between  the  lateral 
and  median  quarters  of  the  transverse  diameter  of  the  strobila,  in  the  median 
frontal  plane,  that  is  below  the  neighboring  testes,  and  with  a  diameter  of  50 
to  lOOju.  The  details  of  the  system  have  been  studied  by  Moniez  (1881), 
Niemiec  (1888),  Zernecke  (1895),  andCohn  (1898),  the  latter  of  whom  found 
conditions  pretty  much  as  in  Schistocephalus,  namely,  that  each  chief  strand 
has  associated  with  it  six  collateral  strands,  arranged  in  three  groups  of  two 
each. 

The  excretory  system  was  studied  by  Moniez  and  Zernecke  in  considerable 
detail.  Linstow  stated  that  two  regions  accommodating  numerous  longi- 
tudinal vessels  are  present:  (1)  an  outer,  close  beneath  the  vitelline  glands, 
and  (2)  an  inner,  between  the  inner  longitudinal  and  transverse  muscles,  or  as 
Linstow  figured,  between  the  former  themselves.  In  the  material  studied  an 
outer  plexus  appeared  close  beneath,  among,  or  most  often  just  outside  of  the 
vitelline  glands  (cortical);  a  second  and  quite  indistinct  one  among  both  sets 
of  muscles,  and  a  third,  or  innermost  layer,  as  prominent  as  the  outermost, 
almost  in  the  median  frontal  plane  of  the  medulla. 

The  sets  of  genitalia,  beginning  about  10mm.  from  the  anterior  end  and 
very  closely  crowded  together  in  the  longitudinal  direction,  lie  from  0.05  to 
0.20mm.  apart,  0.13  to  0.15mm.  being  the  data  given  by  Linstow.  The  open- 
ings are  usually  almost  exactly  in  a  transverse  line;  but  the  cirrus  and  uterus 
openings  alternate  irregularly  from  side  to  side,  that  of  the  vagina  being  con- 
stantly in  the  middle.  This  alternation  of  the  openings  is  due  to  the  similar 
alternation  of  the  internal  organs  and  evidently  was  the  basis  upon  which  the 
earlier  species  L.  digramma  and  L.  alternans  were  established.  The  genital  cloaca 
is  a  quite  irregular  transverse  depression,  0.18  to  0.20mm.  in  width  and  0.02 
to  0.03mm.  in  length,  the  respective  measurements  by  Linstow  being  0.106 
and  0.026mm. 

"The  testes  lie  in  a  single  row,  which  is  only  interrupted  by  the  uterus,  on 
the  dorsal  side  of  the  medulla.  ..."  They  are  from  20  to  40  in  number  in 
transections,  ellipsoidal  in  shape,  their  greatest  diameters  being  transverse,  as 
indicated  by  the  maximum  width,  length,  and  depth  being,  respectively,  115  to 
145,  45  to  55,  and  80  to  85ai.  Linstow  gave  them  as  150  to  180/i  long  by  88  to 
156/x  wide.    The  loosely  coiled  vas  deferens  is  situated  above  the  cirrus-sac 


3151  PSEUDOPHYLLIDEA  FROM  FISHES— COOPER  27 

(Fig.  78)  and  roughly  divided  into  two  parts  by  the  lateral  coils  of  the  uterus, 
one  part  being  immediately  above  the  cirrus-sac  and  the  other  close  to  the 
dorsal  body  wall.  The  duct  attains  a  diameter  of  35jLt  when  filled  with  sper- 
matozoa. Distally  it  expands  into  the  very  small  (as  compared  to  that  of 
Sch.  solidus)  seminal  vesicle,  situated  close  to  the  dorsal  wall  of  the  cirrus-sac. 
The  vesicle  is  from  65  to  100/i  in  length  by  40  to  90/z  in  diameter  (156  by  86/x, 
Linstow),  oval  in  shape,  the  narrov^^er  end  towards  the  cirrus  pouch,  and  pro- 
vided with  only  a  comparatively  feeble  musculature.  The  wall  of  the  struc- 
ture is  richly  supplied  both  internally  and  externally  with  nuclei  which  are 
respectively  those  of  the  lining  epithelium  and  the  myoblasts,  as  in  Schisto- 
cephalus.  The  epithelium  is  strongly  ciUated.  The  cirrus-sac  (Fig.  78)  is  an 
ovoid  body,  somewhat  flattened  dorso-ventrally  and  obliquely  by  the  uterus, 
and  alternating  irregularly  from  right  to  left,  always  occupying  the  opposite 
side  of  the  median  line  from  the  ovarian  isthmus  and  the  neighboring  female 
ducts.  Its  wall  is  quite  thin,  while  apart  from  the  cirrus  proper  which  occupies 
the  distal  two-thirds,  the  contents  consist  of  loose  parenchyma  and  only  a  few 
retractor  muscles.  The  measurements  of  the  organ  in  sections  are:  dorsoven- 
tral  diameter,  185  to  215;  width,  130  to  160;  and  length,  130  to  145^;  which  are 
quite  at  variance  with  Linstow's  diameter  of  53fi  of  what  he  described  as  a 
spherical  organ.  Within  the  cirrus-sac  the  vas  deferens  is  not  sharply  separated 
into  ejaculatory  duct  and  cirrus  proper,  altho  the  latter  is  quite  distinct,  closely 
coiled,  and  as  much  as  25/x  in  diameter. 

The  vagina  opens  into  the  common  genital  cloaca,  if  one  may  use  that  name 
for  the  depression  mentioned  above,  in  the  median  line  and  usually  equidistant 
from  the  openings  of  the  cirrus  and  uterus.  It  passes  dorsally  thru  the  cortex 
and  the  musculature  with  almost  a  straight  course.  Then  within  the  medulla 
it  turns  sharply  posterolaterally,  in  which  portion  of  its  course  it  has  a  diameter 
of  from  15  to  SO/jl  (5/x,  Linstow).  Its  thin  lining  of  cuticula,  directly  continuous 
with  that  of  the  genital  depression,  gradually  passes  into  a  nucleated  epithelium, 
in  which  no  distinct  cell  boundaries  appear,  just  within  the  cortex.  Dorsal  to 
the  ovarian  isthmus  it  enlarges  into  an  elongated  receptaculum  seminis  which 
has  a  diameter  of  from  75  to  90/x.  Linstow  described  a  spindle-shaped  terminal 
receptacle,  13/x  in  diameter,  and  an  oocapt  as  follows:  "dorsal  von  der  Ver- 
einigungsstelle  der  beiden  Keimstocksfliigel  liegt  der  ovale,  0.088mm.  lange  und 
0.066mm.  breite  Schluckapparat " ;  each  of  which,  however,  in  comparison  with 
that  described  here  by  the  writer  and  for  Sch.  solidus  below,  seems  to  have  been 
confused  with  the  other.  At  least  the  oocapt  of  none  of  the  bothriocephalids 
described  here  is  relatively  so  large  as  indicated  by  Linstow  in  his  measurements 
and  in  his  figure,  nor  is  the  receptaculum  as  spindle-shaped  as  shown  in  the 
latter.  In  this  connection  Kiessling  described  a  swelling  of  the  vagina,  46/x  in 
diameter,  which  contained  spermatozoa.  The  spermiduct  is  so  short  and  of 
such  a  small  calibre  that  it  is  quite  difficult  to  locate  it  in  sections.  After  pur- 
suing a  horizontal  course  it  unites  with  the  oviduct  a  short  distance  from  the 
oocapt  (Fig.  98)  much  as  in  Sch.  solidus.  It  is  from  20  to  25m  in  length  and 
6  to  12/i  in  diameter.    The  ovary  is  asymmetrical,  as  stated  by  Kiessling  but 


23  ILLINOIS  BIOLOGICAL  MONOGRAPHS  [316 

denied  by  Linstow,  since  it  consists  of  a  much  depressed  lateral  wing,  situated 
close  to  the  ventral  musculature  (Fig.  78)  and  a  more  median  enlarged  portion 
which  fimctions  as  the  isthmus  in  that  the  oviduct  arises  from  it.  This  isth- 
mus-like region  is  not  in  the  median  line  but  about  0.25mm.  frotn  it,  the  whole 
organ  alternating  irregularly  from  right  to  left,  constantly  opposing  the  cirrus- 
sac  on  the  other  side.  It  varies  from  0.55  to  0.64  mm.  in  width  and  has  a 
length  laterally  of  0.12mm.  Its  imusual  situation  is  evidently  due  to  the 
closely  crowded  condition  of  the  reproductive  organs  and  the  pressure  exerted 
by  the  large  uterus  in  the  median  line.  Whereas  the  wing  has  a  maximum 
dorsoventral  diameter  of  about  60/x,  the  isthmus  is  ^bout  95/i  in  depth  and 
roughly  ellipsoidal  in  shape,  protruding  in  sections  from  the  dorsal  region  of  the 
junction  of  the  wing  (Fig.  78).  Ova  from  the  isthmus  were  found  to  be  oval 
to  spherical  in  shape  and  from  12  to  15ju  in  diameter  (13  to  16^t,  Linstow).  The 
oocapt  is  directed  horizontally  away  from  the  side  of  the  isthmus  and  from  the 
median  line.  Its  diameter  is  from  18  to  20/i, — with  which  compare  the  dimen- 
sions of  88  by  66ju  given  by  Linstow.  The  oviduct  has  a  diameter  of  from  15 
to  20/i.  Taking  a  general  dorsal  course,  after  being  joined  by  the  spermiduct, 
it  soon  receives  the  common  vitelline  duct  (Fig.  98)  which  has  only  a  limited 
enlargement  from  a  previous  diameter  of  10  to  20  to  30/u  in  the  form  of  a 
vitelline  reservoir,  located  close  to  the  oviduct  with  a  length  of  40/x.  The 
vitelline  follicles  are  situated  in  a  layer  close  beneath  the  subcuticula  and  un- 
broken, excepting  in  the  median  ventral  line.  The  individual  follicles,  very 
irregular  in  shape,  are  50  to  70/x  in  depth  and  15  to  30/t  in  width,  Linstow's 
measurements  being  65  by  47m  and  Kiessling's  6/i  in  the  larva.  Concerning  the 
shell-gland  Linstow  said:  "Die  Schalendriise  ist  ein  0.088-0. 105mm.  grosses 
Organ,  das  dorsal  von  der  Mitte  des  einen  Keimstockfliigels  an  der  entsprechen- 
den  Aussenwand  der  Uterus  liegt;  die  Zellen,  deren  kleiner  Kem  sich  intensiv 
farbt,  sind  0.0039mm.  gross."  In  the  sections  studied  by  the  writer  it  was 
found  to  be  a  quite  irregular  structure,  composed  of  greatly  elongated  club- 
shaped  cells  with  necks  of  different  lengths  which  unite  with  the  oviduct  in  a 
region  only  about  30jli  in  length  and  situated  just  beyond  the  point  of  reception 
of  the  common  vitelline  duct  (Fig.  98).  These  cells  are  so  loosely  arranged  and 
their  proximal  attenuated  portions  of  such  a  filiform  nature  that  they  are  very 
easily  overlooked,  especially  since  they  are  scattered  thruout  the  whole  of  the 
dorsoventral  diameter  of  the  medulla  of  the  region  and  are  interwoven  among 
the  oviduct,  the  receptaculum,  the  vitelline  duct  and  the  beginning  of  the 
uterus.  They  form  by  no  means  such  a  compact  organ  as  Linstow's  descrip- 
tion and  figure  would  indicate.  The  distal  ends  of  the  cells  are  about  15  by 
lOjLi  in  size,  while  their  nuclei  are  about  4/x  in  diameter.  Kiessling  described 
the  shell-gland  as  similar  to  that  of  Sch.  solidus,  and  as  follows:  "Die  Schalen- 
driise besteht  aus  Driisenzellen,  welche  an  feinen  Stielchen  befindhche  Blaschen 
an  der  Oberflache  einer  Halbkugel  angeordnet  sind  imd  ihre  Stielchen  als 
Radien  nach  dem  Mittelpunkte  der  Kugel  senden. "  His  figures  of  such  a 
compact  region  are  likewise  quite  different  from  conditions  described  here. 
The  uterus  forms  a  mass  of  coils,  0.4  to  0.6mm.  in  diameter  in  the  median 


317]  PSEUDOPHYLLIDEA  FROM  FISHES— COOPER  29 

line,  from  which  a  straight  portion  passes  ventrally  thru  the  musculature  and 
cortex  to  the  opening  which  is  about  20/i  in  diameter  (35ju,  Linstow).  The 
diameter  of  the  duct  is  60^  in  the  median  frontal  plane  but  only  half  that 
amoimt  as  it  passes  thru  the  longitudinal  muscles.  The  measurements  of  the 
eggs  are  according  to  Kiessling  and  Linstow,  respectively,  49  by  34jli  and  65  by 
42fjL:  they  were  found  by  the  writer  to  be  50  to  54  by  30  to  33iJ.  in  sections. 

Our  knowledge  of  the  life-history  of  the  species  is  confined  chiefly  to  the 
works  of  Duchamp  (1876),  Donnadieu  (1877)  and  Riehm  (1882)  who  firmly 
established  the  well-known  fact  that  the  larva  present  in  the  abdominal  cavities 
of  various  species  of  teleosts  develops  rapidly  in  the  intestines  of  fish-eating 
birds.  The  production  of  eggs  begins  after  about  36  hours,  while  the  adults 
live  for  from  three  to  four  days  only  in  the  definitive  hosts.  Apart,  however, 
from  these  and  other  closely  related  details  which  were  brought  out  by  Donn- 
adieu by  means  of  well  conducted  and  controlled  experiments,  nothing  is 
known,  so  far  as  the  writer  is  aware,  of  the  development  of  the  oncosphere  in 
the  intermediate  host  up  to  the  time  when  it  becomes  distinguishable  as 
a  small  larva.  The  measurements  of  the  smallest  larva  found  in  connection 
with  this  study  have  been  given  above;  another  slightly  larger  specimen 
was  6.1mm.  in  length  by  1.34mm.  maximum  breadth. 

Altho  the  above  description  shows  many  discrepancies  between  the  species 
as  here  dealt  with  and  the  European  form,  the  writer  does  not  feel  justified  in 
separating  the  two  specifically,  especially  in  the  absence  of  European  material 
for  comparison.  The  thickness  of  the  cuticula,  and  subcuticula,  the  dimen- 
sions of  the  testes,  seminal  vesicle  and  cirrus-sac  and  the  diameter  of  the 
vagina  show  the  greatest  differences,  apart  from  the  probable  confusion  by 
Linstow  of  the  oocapt  and  receptaculum  seminis,  while  the  measurements  of 
the  eggs  as  here  given  are  somewhat  intermediate  between  those  by  Kiessling 
and  Linstow.  But  the  fact  that  the  data  given  by  the  latter  are  apparently 
the  only  adequate  ones  for  the  adult  and  that  there  are  not  a  few  discrepancies 
between  Kiesshng's  and  Linstow's  accounts  restrains  one  from  looking  upon 
this,  the  American  form,  as  new.  In  deaUng  with  this  question  of  identity 
it  must  also  be  remembered  that  not  only  does  the  species  vary  so  much  that, 
as  pointed  out  above,  a  great  deal  of  confusion  exists  in  the  earher  Uterature, 
but  that  the  number  of  host  species  of  the  larva  as  well  as  of  the  adult  is  very 
large  as  compared  to  other  species  of  bothriocephaHds,  hence  introducing 
greater  factors  for  variation.  And  above  all  the  geographical  distribution  of 
the  wading  and  diving  birds  harboring  the  mature  worms  is  such  that  here  in 
America  there  are  many  of  the  same  species  as  well  as  the  same  genera  that 
occur  in  Europe.  As  the  above  record  of  hosts  indicates,  the  species  certainly 
ranges  widely  over  Europe  and  Northern  Asia,  so  that  it  would  be  quite  sur- 
prising if  it  did  not  occur  here  in  North  America,  with  the  probable  region 
of  transition  in  Iceland  and  Greenland  on  the  east  and  northeastern  Siberia 
and  Alaska  on  the  west.  However  apart  from  Leidy's  and  Linton's  records  it 
has  apparently  not  been  reported  up  to  the  present. 


30  ILLINOIS  BIO  LOGIC  A  L  MONOGRA  PHS  [3 1 S 

The  material  studied  by  the  writer  consisted  of  the  following  lot  of  larvae: 
Nos.  4706  and  4708  of  the  collection  of  the  United  States  National  Museum ; 
Ch  18a,  16.411,  16.413,  16.414,  16.419,  17.31  and  17.32  of  the  collection  of  the 
University  of  Illinois,  under  the  care  of  Professor  H.  B.  Ward;  Nos.  49b,  70 
to  79, 110  to  119,  361  to  370, 427  and  431c  of  the  collection  of  Dr.  G.  R.  LaRue; 
Nos.  II,  III,  IV,  and  V  from  the  collection  of  Mr.  H.  R.  Hill;  and  Nos.  47, 
54,  150,  158,  159,  160,  189,  190,  312,  313,  314,  317,  319,  and  330  of  the  writer's 
collection;  and  the  adults  contained  in  Nos.  La  156,  17.184,  and  17.185  of  the 
collection  of  the  University  of  Illinois,  respectively  from  the  intestines  of 
Merganser  sp.,  Podilymhus  podiceps  and  Colymbus  holboellii,  and  No.  387g  of  the 
collection  of  Dr.  LaRue  from  the  intestine  of  Mergus  merganser. 

SCHISTOCEPHALUS  Creplin  1829 


Taenia  (part.) 

Auctorum 

Hirudo  (part.) 

Linnaeus 

1745 

Fasciola  (part.) 

Linnaeus 

1767 

Rhytis  (part.) 

Zeder 

1800 

Halysis  (part.) 

Zeder 

1800 

Bothriocephalus 

(part.) 

Rudolphi 

1808 

Schistocephalus  (part.) 

Creplin 

1829 

Bothria  and  external  segmentation  developed  in  the  larva.  The  tip  of  the 
scolex  retractile.  Segmentation  complete  and  corresponding  to  the  .internal 
structure  of  the  animal.  Longitudinal  and  transverse  muscles  arranged  in 
several  alternating  layers  (three  transverse  layers  enclosing  two  longitudinal 
layers). 

Type  (and  only)  species:  Schistocephalus  solidus  (O.  F.  Miiller). 

SCHISTOCEPHALUS  SOLIDUS  (O.  F.  Miille!  1776) 
[Figs.  3,  79,  80] 

LARVAL  stage: 


1734 

Taenia 

Frisch 

1734 

:395 

1745 

Hiriido  depressa  alba 

Linnaeus 

1745 

:2S0 

1758 

Fasciola  hepatica 

Linnaeus 

1758 

:648 

1761 

Taenia  lata 

Pallas 

1761 

:410 

1767 

Fasciola  hepatica 

Linnaeus 

1767 

:1077 

1776 

Taenia  solida 

MuUer 

1776 

:219 

1780 

Taenia  gasterostei 

Miiller 

1780 

:22 

1780 

Taenia  gasterostei 

Fabricius 

1780 

:320 

1781 

Taenia  acutissima 

Pallas 

1781 

:  76,  78 

1786 

Taenia  gasterostei 

Batsch 

1786 

:224 

1788 

Taenia  solida 

Schrank 

1788 

:49 

1790 

Taenia  solida 

Gmelin 

1790 

:3079 

1790 

Taenia  gasterostei 

Abildgaard 

1790  : 

:  49-58 

1800 

Rhytis  solida 

2Leder 

1800 

:297 

1810 

Bothriocepltalus  solidus 

Rudolphi 

1810  ; 

;57 

1819 

Bothriocephalus  solidus 

Rudolphi 

1819  : 

: 139,  477 

1819 

Bothriocephalus  solidus 

Leuckart 

1819  : 

46 

3191 


PSEUDOPHYLLIDEA  FROM  FISHES— COOPER 


31 


1824  Bothriocephdus  solidus 

1829  Bothriocephdus  solidus 

?  1863  Schistocephdus  rhynchich- 
thydis 

1896  Schistocephalus  dimorphus 

1896  Schistorhynchus  dimorphus 

1898  Schistocephdus  dimorphus 

1898  Schistocephdus  solidus 

1898  Schistocephdus  solidus 

1899  Schistocephdus  solidus 
1909  Schistocephdus  solidus 

ADULT  stage: 

1782  Taenia  lanceolata  nodosa 

1786  Taenia  lanceolata  var.  /3 

1788  Taenia  nodularis 

1790  Taenia  lanceolata  nodosa 

1790  Taenia  gasterostei 

1793  Taenia  lanceolata  nodosa 

1800  Edysis  lanceolato  nodosa 

1810  Bothriocephalus  nodosus 

1819  Bothriocephdus  nodosus 

1819  Bothriocephdus  nodosus 

1824  Bothriocephdus  nodosus 

1829  Schistocephdus  dimorphus 

1839  Schistocephalus  dimorphus 

1845  Schistocephdus  dimorphus 

1850  Schistocephalus  dimorphus 

1853  Schistocephdus  dimorphus 

1854  Schistocephalus  dimorphus 

1858  Schistocephalus  solidus 

1859  Schistocephdus  solidus 
1863  Schistocephalus  dimorphus 
1869  Schistocephdus  dimorphus 
1877  Dibothrium  ligula 

1881  Schistocephalus  dimorphus 

1882  Schistocephdus  dimorphus 

1889  Schistocephalus  solidus 

1890  Schistocephalus  dimorphus 
1893  Schistocephalus  dimorphus 
1896  Schistocephdus  dimorphus 
1896  Bothriocephalus  zschokkei 
1898  Schistocephdus  zschokkei 

1898  Schistocephalus  solidus 

1899  Schistocephdus  nodosus 

1900  Schistocephdus  dimorphus 

1910  Schistocephdjts  gasterostei 

1911  Schistocephdus  dimorphus 


Nitzsch 

1824  ; 

97 

Baer 

1829  ; 

:388 

Diesing 

1863  ; 

:233 

Zschokke 

1896  ; 

;773 

Zschokke 

1896 

:776 

Linton 

1898  ; 

:427 

Cohn 

1898 

:126 

Miihling 

1898  : 

.33 

Liihe 

1899  : 

:52 

Scott 

1909 

:80 

Bloch 

1782  1 

flO 

Batsch 

1786  ; 

:167 

Schrank 

1788  : 

;39 

Gmelin 

1790; 

:3075 

Abildgaard 

1790  : 

;  49-58 

Rudolph! 

1793 

:41 

Zeder 

1800 

:340 

Rudolph! 

1810 

:54 

Rudolph! 

1819 

:140 

Leuckart 

1819 

:58 

N!tzsch 

1824 

:97 

CrepUn 

1829 

:95 

Creplin 

1839 

:296 

Dujardin 

1845 

-.622 

D!es!ng 

1850 

-.584 

Baird 

1853 

:92 

Diesing 

1854 

:19 

R.  Leuckart 

1858 

:129 

Steenstrup 

1859 

:475 

Diesing 

1863 

:232 

Willemoes-Suhm 

1869 

:469 

Donnadieu 

1877 

:495 

Monniez 

1881 

:175 

Kiessling 

1882 

Lonnberg 

1889 

:40 

Lonnberg 

1890 

:18 

Olsson 

1893 

:15 

Ariola 

1896 

:280 

Fuhrmann 

1896 

Fuhnnann 

1898 

:144 

Miihling 

1898 

:33 

Liihe 

1899 

:52 

Ariola 

1900 

:426 

Luhe 

1910 

:19 

Solowiow 

1911 

:123 

Specific  diagnosis :  With  the  characters  of  the  genus.  Medium  sized  worms, 
length  30  to  300mm.,  breadth  3  to  9mm.  First  segment  or  "  scolex  "  0.4  to  0.8mm. 
in  length  and  1  to  1.3mm.  in  width.  Strobila  ovate-lanceolate  and  depressed, 
maximum  breadth  anterior  to  the  middle;  hindermost  segments  narrower  and 


32  ILUNOIS  BIOLOGICAL  MONOGRAPHS  [320 

flatter,  0.25  to  1.0mm.  in  length  by  1  to  3mm.  in  width,  forming  an  appendage 
up  to  10mm.  in  length;  medium  segments  0.1  to  0.5mm.  long,  posterior  borders 
prominent.     Shallow  median  groove  on  the  ventral  surface. 

Cuticula  15  to  20/z  in  thickness;  subcuticula  40  to  65jli.  Layer  of  internal 
longitudinal  muscles  15  to  50ju  in  thickness.  Nerve  strands  30  to  75;Li  in  diame- 
ter.    25  to  30  excretory  vessels  in  transections. 

Genital  cloaca  median,  shallow,  \vith  a  diameter  of  90^;  no  hermaphroditic 
duct.  Opening  of  \Tigina  close  behind  that  of  cirrus  and  to  one  side  but  not 
so  far  as  that  of  the  uterus,  both  alternating  irregularly  from  side  to  side. 

Testes  extend  from  the  median  genital  ducts  laterally  to  the  edges  of  the 
medulla,  unbroken  from  proglottis  to  proglottis,  closely  crov/ded,  240  to  480 
in  nxmiber  for  each  proglottis,  85  to  lOO^n  in  depth,  40  to  65  in  width  and  55  to 
85  in  length.  Vas  deferens  median,  dorsal,  closely  appUed  to  the  seminal  vesi- 
cle, the  whole  mass  0.30mm.  in  diameter,  the  duct  itself  35  to  60/i.  Seminal 
vesicle  1 75  by  150juc,  walls  25/n  in  thickness.  Cirrus-sac  oval  in  shape,  immediate- 
ly below  the  seminal  vesicle,  0.185  to  0.203  by  0.203  to  0.212  by  0.166  to  0.185 
mm.  in  dimensions.  No  inner  seminal  vesicle.  Cirrus  proper  not  sharply 
separated  from  the  ductus  ejaculatorius;  whole  surroimded  by  numerous 
retractor  muscles. 

Vagina  45  to  60/i  in  diameter  just  within  the  medulla.  Receptaculum 
seminis  large,  92  to  IOS/jl  in  diameter.  Spermiduct  unites  with  the  oviduct 
close  to  the  ventral  wall  of  the  medulla.  Ovary  with  large  wings  consisting 
of  closely  arranged  tubules,  whole  organ  0.6mm.  in  width,  wings  0.10  in  length. 
0\'a  13/x  in  diameter,  their  nuclei  5/1.  Oocapt  35  to  40/t  in  diameter,  oviduct 
25  to  30/t.  Vitelline  gland  unbroken  at  margins  of  the  proglottis,  from  proglot- 
tis to  proglottis,  and  medially,  excepting  for  small  areas  above  and  below  the 
proximal  reproductive  ducts;  individual  follicles  55  to  90  by  18  to  26/x. 
Ootj'pe  16  to  20/1  in  diameter.  Shell-gland  shghtly  to  one  side  of  median  line. 
Uterus  85  to  135/x  in  diameter  at  its  middle;  the  terminal  portion  directed 
dorsoventrally  and  lined  with  cuticula  distally;  opening  at  the  bottom  of  a  slight 
invagination  of  the  ventral  body  wall,  formed  by  the  rupture  of  a  pre- 
existing cuticular  membrane. 
Eggs,  38  to  65  by  22  to  38/j. 

Habitat:  As  larvae  in  the  body-cavities  and  occasionally  in  the  stomach 
and  intestine  of  bony  fishes;  adults  in  the  intestines  of  wading  and  diving  birds. 


321] 


PSEUDOPHYLLIDEA  FROM  FISHES— COOPER 


33 


HOST 

LOCALITY 

COLLECTOR 

AUTHORITY 

Larval  stage: 

Gasterosteus  aculeatus 

Greenland 

Fabricius 

Fabricius     1780  :  320 

Cottus  poecilopus 

L.  Storsjon, 
Sweden 

Olsson 

Olsson          1893  :  15 

Cottus  bairdii 

Swan  R.,  Mont. 

Everman 

Linton          1898  :  427 

Salmo  solar 

Basel 

Zschokke 

Zschokke     1896  :  776 

Plioca  vUulitm 

Gryphswald 

Rudolphi 

Rudolphi     1819  :  140 

Rhynchichihys  gronovii 

Hayti 

Weinland 

Diesing        1850  :  585 

Gasterosteus  bispinosus 

Chamcook  L., 

A.  R.  Cooper 

Cooper  (the  present 

atkinsii 

New  Brunswick 

paper) 

Uranidea  formosa 

Port  Credit, 
Ontario 

A.R.Cooper 

Gasteroscus  cataphractiis 

R.  P.  Lake,  St. 
Paul  Id.,  Pribilof 
Ids.,  Alaska 

C.  E.  Crompton 

>>           »> 

Adult  stage: 

Corvus  comix 

East  Prussia 

Braun 

Muehling     1898  :  34 

Recurvirostra  avocetta 

Schilling 

Diesing        1850  :  584 

A  rdea  stellar  is 

Genf 

Fuhrmann 

Fuhrmann   1896  :  546 

Ciconia  alba 

East  Prussia 

Braun 

MuehUng     1898  :  34 

Sterna  hirimdo 

Gryphswald 

Rudolphi 

Rudolphi     1819  :  140 

Colymbus  septentrional  is 

Firenze,  Italy 

Condorelli 

Parona         1899  :  8 

Podiceps  nigricoUis 

Bracciano,  Italy 

Parona 

Parona         1899  :  8 

Larus  ridibundus 

Rossitten 

Muehling 

Muehling     1898  :  34 

Anas  glacialis 
Mergus  senator 

Creplin 
Olsson 

Diesing        1850  :  585 
Olsson          1893  :  15 

L.  Storsjon, 

Jemtland,  Sweden 

Uria  troile 

.Abildgaard 
C.  W.  Stiles 

Diesing        1850  :  585 

Alca  tarda 



Leipzig 

Stiles  and     1894  :  322 

Hassall 

Tetanus  calldrus 

Jaederen,  Xorrtay 

Loennberg 

Loennberg   1890:18 

Harelda  giaciaJis 

Pillau 

Muehling 

Muehling     1898  :  34 

Fzdignla  marila 

Pillau 

Muehling 

Muehling     1898  :  34 

Haematopus  ostrealegus 

Pillau 

Muehling 

Muehling     1898  :  34 

Fidica  atra 

Portoferrajo, 
Id.  Elba 

Damiani 

Parona         1899  :  7 

Puffiniis  kiMi 

Portoferrajo, 
Id.  Elba 

Damiani 

Parona         1899  :  7 

Urinator  arcticus 

Luhe            1910  :  19 

Stercorarius  parasiticus 

Luhe            1910  :  19 

Nyroca  marila 

Luhe            1910  :  19 

Lophodytes  cucullatus 

Lincoln,  Nebr. 

H.  B.  Ward 

1 

Cooper  (the  present 
paper) 

The  species  has  also  been  reported  in  Europe  from  the  following  additional 
hosts: 

Larval  stage:  Cottus  scorpio,  Fulica  atra,  Gasterosteus  pungitius,  Totanus 
calidrus,&ndRanaesculentc; 


34  ILLINOIS  BIOLOGICAL  MONOGRAPHS  [322 

Adult  stage:  Alca  pica,  Ardea  cinerea,  Ciconia  ciconia,  C.  nigra,  Colymbus 
arcticus,  C.  cristatus,  C.  glacialis,  C.  griseigena,  C.  immer,  C.  troile,  Corvus 
corax,  Larus  argentaius,  L.  capistranus,  L.  marinus,  Mergus  alheUus,  Mergus 
merganser,  Podiceps  cristatus,  P.  rubricollis,  Sterna  arctica,  S.  macroura,  S.  minuta, 
S.  nigra  and  Uria  grylle. 

As  indicated  in  the  above  synonymy  this  species  was  known  for  ahnost  a 
century,  at  first  as  the  larval  form  only  and  then  as  both  larval  and 
adult  forms,  before  it  was  discovered  that  the  two  species  recognized 
from  the  time  of  Bloch  (1782)  were  one  and  the  same.  Abildgaard  (1790), 
who  called  the  worm  T.  gasterostei,  seems  to  have  been  the  first  to  consider  the 
larval  form  foimd  chiefly  in  sticklebacks  to  be  the  same  as  that  found  in  fish- 
eating  birds,  since  on  feeding  sticklebacks  infected  with  the  larvae  to  geese 
he  obtained  the  adult  form  from  the  intestines  of  the  latter.  Yet  Rudolphi 
(1810)  did  not  agree  with  his  conclusions  but  still  considered  that  there  were 
two  distinct  species,  namely,  Bothriocephalus  nodosus  (adult)  and  B.  solidus 
(larva).  And  this  continued  until  Creplin  (1829)  united  both  in  one  species 
under  a  new  genus,  Schistocephalus  dimorphus.  Diesing  (1863:233)  made  a 
new  species  out  of  the  Schistocephalus  found  by  Weinland  (1859)  in  the  island 
of  Hayti  in  Rhynchichthys  gronovii,  but  later  writers  have  considered  that  in 
all  probability  it  was  only  the  well  known  larval  form  of  this  species.  Wille- 
moes-Suhm  (1869)  was  evidently  the  first  to  study  the  development  of  the 
fertilized  oviun,  which  was  later  gone  into  more  thoroughly  by  Schauinsland 
(1885:555).  Donnadieu  (1877),  to  whom  all  go  back  in  their  considerations 
of  the  larval  development  of  Ligula,  unfortunately  fell  into  the  error  of  con- 
sidering Schistocephalus  and  Ligula  to  be  not  only  the  same  specifically  but 
generically.  The  anatomy  ^\'as  first  studied  by  Moniez  (1881:175),  more 
thoroughly  by  Kiessling  (1882),  and  still  later  by  Furhmann  (1896)  (under  B. 
zschokkei  sp.  nov.)  and  Solowiow  (1911).  Linton  (1897:427)  is  the  only  one, 
apart  from  Weinland's  record  which  is  only  a  brief  foot  note,  who  has 
reported  the  species  from  America. 

As  regards  the  correct  name  of  the  species,  it  should  be  noted  that,  altho 
Liihe  (1899:52)  called  the  "typical  and  only  species"  of  the  genus  Sch.  nodosus 
(Rud.)  and  the  larval  stage  Sch.  solidus  (O.  F.  Mliller),  he  reverted  in  1910 
to  "Schist,  gasterostei  {Fabr.)  (  =  Sch.  dimorphus  Crepl.)"  without,  however, 
discussing  the  change.  But  according  to  the  Rules  of  Nomenclature,  Art. 
27  (b),  the  earliest  name  of  the  larval  stage  must  hold,  so  that,  since  Liihe 
himself  considered  this  to  be  Sch.  solidus  (O.  F.  Miiller),  the  writer  makes 
use  of  the  latter  in  the  present  paper. 

According  to  Luhe  (1910:19)  Sch.  solidus  ranges  in  length  from  30  to  300mm. 
while  the  maximum  breadth  varies  from  about  3  to  9mm.  and  is  located  ahead 
of  the  middle  of  the  strobila.  As  shown  in  the  table  below  the  largest  and  only 
sexually  mature  specimen  of  the  six  studied  by  the  writer  was  only  29mm.  in 
length  by  6mm.  in  breadth.  The  scolex  (Fig.  3)  is,  as  indicated  in  the  above 
diagnosis  of  the  subfamily,  not  separated  from  the  first  segment  into  which  it 
runs  insensibly,  the  whole  "  head  "  being  thus  triangular  in  shape.    The  bothria 


3231  PSEUDOPHYLLIDEA  FROM  FISHES— COOPER  35 

are  merely  short  median  grooves  which  unite  at  the  very  tip  not  only  with  each 
other  but  with  a  frontal  median  groove  which  passes  laterally  into  sUght  emar- 
ginations  of  the  edges  of  the  segments.  While  these  emarginations  were  seen 
to  be  present  in  the  anterior  segment,  gradually  disappearing  towards  the  mid- 
dle of  the  worm,  no  such  "flat  leaflike  flaps  (bothria)  on  the  lateral  margins 
separated  from  each  other  on  flat  surface  by  a  broad,  shallow  sulcus, "  as  de- 
scribed by  Linton  (1898:428)  and  shown  in  his  Fig.  4,  PI.  XXVIII,  for  the 
first  segment  were  met  with;  but  the  posterior  border  was  quite  entire,  altho 
as  seen  in  figure  3,  not  very  prominent  in  the  vicinity  of  the  median  li^e  in 
adults  as  well  as  in  larvae.  The  bothria  of  the  mature  specimen  (H.  7  of  the 
table  below)  were  not  present,  but  the  region  where  they  would  otherwise  be 
was  quite  smooth,  only  a  shallow,  median,  frontal  groove  appearing.  The  whole 
strobila  is  ovate-lanceolate,  considerably  depressed  and  provided  in  the  adult 
with  a  very  shallow  median  groove  on  the  dorsal  surface  (Fig.  80)  which  seems 
to  be  due  to  the  sUght  protrusion  of  the  median  reproductive  organs,  chiefly 
the  cirrus-sacs  and  seminal  vesicles,  towards  the  ventral  surface  (Fig.  79)  and 
the  consequent  dragging  downward  of  the  dorsal  median  tissues.  Concermng 
this  matter  Linton  said  "5.  dimorphus  is  described  as  having  in  the  larval 
state  a  longitudinal  median  furrow  on  each  face.  These  specimens  do  not 
exhibit  this  character;  neither  do  they  have  anything  that  can  be  properly 
called  a  costa  dividing  the  two  bothria. "  While  in  the  specimens  studied  the 
dorsal  groove  was  present  not  only  in  the  adult  but  (not  so  well  marked)  in 
the  larva,  a  similar  ventral  groove  was  also  noticed  in  sections  of  the  anterior 
end  of  one  of  the  latter.  Both  grooves,  however,  are  in  either  case  so  shallow 
as- to  be  easily  overlooked  in  alcoholic  specimens;  they  seem  to  be  of  only  second- 
ary importance  since  they  are  apparently  quite  variable  in  their  nature.  While 
the  segments  in  the  anterior  region  of  the  strobila  are  very  broad  and  com- 
paratively thick,  short,  and  from  0.1  to  0.5mm.  in  length,  posteriorly  the  stro- 
bila is  considerably  smaller  and  flatter,  especially  in  mature  individuals.  In 
larvae  the  segments  are  much  more  irregular  in  outline  and  as  much  as  1mm, 
long  (0,75  in  the  only  ripe  specimen  studied).  The  segmented  condition  of 
the  strobila,  in  contrast  with  that  of  Ligula,  is  rendered  more  apparent  by  the 
prominent  posterior  borders  of  the  anterior  and  middle  proglottides  which  at 
the  margins  produce  the  characteristic  saw-tooth  effect.  The  following 
table  gives  the  measurements  of  two  specimens  with  those  by  Linton  for 
comparison : 


36 


ILUNOIS  BIOLOGICAL  MONOGRAPHS 


[324 


4727  Tj.  s.  N.  M. 


Length 

17mm. 

29mm. 

52mm. 

Maxim-oia  breadth 

5.5 

6 

6 

Length  of  "cauda" 

1.64 

10 

? 

Breadth  of  same 

1.1 

2-3 

2.5 

Length  of  med.  segs. 

0.16 

0.27-0.46 

0.25 

Length  of  post.  segs. 

0.25-0.40 

0.4O4).75 

? 

Length  of  first  seg. 

0.46 

0.46 

0.80 

Breadth  anteriorly 

0.48 

0.46 

0.80 

Breadth  posteriorly 

1.11 

1.11 

1.30 

Length  of  bothrium 

0.07 

Absent 

p 

Condition 

Lar\-al 

Adult 

Larval 

Since  the  essential  features  of  the  internal  anatomy  of  this  species  have 
been  worked  out  by  the  European  workers,  only  the  striking  similarities 
and  differences  to  and  from  the  data  given  in  particular  by  Kiessling,  Fuhr- 
mann  and  Solowiow  will  here  be  dealt  with  in  support  of  the  writer's  contention, 
in  the  absence  of  European  material  for  comparison,  that  here  in  America 
we  have  the  same  species  as  that  found  in  Europe.  It  will  be  considered  that, 
as  brought  out  by  Liihe  in  three  controversial  papers  (1897, 1897b,  1899a:715) 
and  by  Cohn  (1898:126,  footnote),  S.  zschokkei  Fuhrmann  1898  is  s>'nonymous 
with  5.  solidus.  As  a  matter  of  fact  many  of  the  data  given  below  wiU  be  seen 
to  compare  more  favorably  with  those  published  by  Fuhrmann  than  with 
those  by  either  Kiessling  or  Solowiow. 

According  to  Kiessling  the  cuticula  is  from  15  to  18^  in  thickness  and  divisible 
into  two  layers,  of  which  the  inner  and  lighter  is  from  8  to  9n  thick,  while 
the  outer  is  striated  or  granular.  Fuhrmann  described  a  cuticiila  only  7n  in 
thickness  and  divided  into  two  layers,  and  Solowiow  gave  the  thickness  of 
the  "homogeneous  cuticula"  as  23/x.  Minckert  (1905a :402)  said  that  the 
comidian  or  pseudociliated  layer,  present  in  many  bothriocephalids,  was  quite 
evident  in  5.  nodosus  but  absent  on  the  posterior  borders  of  the  proglottides. 
Here  the  cuticula  was  foimd  to  be  15/t  in  thickness,  excepting  on  the  posterior 
borders  where  it  is  only  5/x,  and  divisible  into  two  layers,  the  outer  of  which, 
a  little  thinner  than  the  inner,  was  much  lighter,  granular  in  consistency  or 
somewhat  striated  with,  however,  a  more  or  less  uniform  external  boimdary. 
It  seems  to  be  easily  separated  from  the  inner  stratum,  the  botmding  line,  in 
reality  the  innermost  portion  of  the  external  layer,  being  in  most  places  very 
light.  In  fact  the  brightness  of  this  inner  layer  of  the  outer  stratvun  indicates 
the  degree  of  separation  of  the  two  layers  in  the  process  of  sloughing  off  the 
outer,  which  can  be  easily  followed  in  sections  as  described  by  Kiessling.  This 
description  however,  applies  only  to  the  adult  stage.  In  larvae  the  cuticula, 
altho  of  the  same  thickness,  shows  an  outer  decidedly  pseudociliated  layer  only 
4^  in  depth.  The  subcuticula,  88.5/i  in  thickness  in  the  median  Une  according 
to  Solowiow,  was  found  to  be  from  40  to  about  65.u,  Kiessling  ha\'ing  given 
the  limits  as  from  29  to  38/i.    While  the  parenchvTna  is  as  described  by  the 


325]  PSEUDOPHYLLIDEA  FROM  FISHES— COOPER  37 

authors,  very  fine  meshed,  calcareous  bodies  are  present  in  comparatively 
small  numbers,  particularly  just  beneath  the  subcuticula  of  the  larva.  Their 
maximum  dimensions  are  23  by  13/:. 

The  musculature  has  been  well  described  by  Kiessling  and  Fuhrmann,  so 
that  it  needs  only  to  be  added  that  in  sections  of  mature  proglottides  the  outer- 
most layer  of  transverse  muscles  as  well  as  the  outer  longitudinal  layer  are 
much  less  numerous  and  hence  well  defined  than  in  the  larva.  Whereas 
Kiessling  gave  the  thickness  of  the  external  and  internal  longitudinal  groups, 
which  on  account  of  their  compact  nature  were  found  to  be  more  uniform  in 
thickness  than  the  transverse  layers,  as  8  to  3)2)  and  16  to  49^,  respectively, 
and  Fuhrmann  as  4  and  8/i,  the  writer  found  them  to  be  17  and  30  to  iO/x. 

The  nervous  system  was  first  studied  in  detail  by  Niemiec  (1888:9)  and 
later  more  thoroughly  by  Colm  (1898:126)  who  summarized  its  structure  in 
the  following  words:  "Von  dem  vordersten  Theil,  den  Ganglien  und  der 
Commissur,  ziehen  die  Hauptstrange  und  12  Nebennerven  riickwarts  [six 
associated  with  each  chief  strand].  Die  Nebennerven  theilen  sich  dichoto- 
misch  in  zwei  Ebenen,  der  frontalen  und  radiaren,  ein  Theil  des  Theilfasem 
riickt  zwischen  aussere  Transversal-  und  Langsmuskeln,  der  andere  bleibt 
weiter  nach  innen  zu  zuriick,  und  diese  Nerven  treten  einerseits  unter  einander 
durch  Ringcommissuren,  andrerseits  durch  radiare  Fasem  mit  den  Haupt- 
nerven  in  Verbindung. "  Kiessling  gave  the  diameter  of  the  chief  nerve 
strands  as  38ju  and  Solowiow  as  67.9/i;  here  they  were  found  to  be  from  30  in 
mature  proglottides  to  75^i  in  the  anterior  segments.  The  ganglia  have  a 
diameter  of  from  55  to  85/i,  as  compared  with  77/x  of  Kiessling. 

In  transections  from  25  to  30  excretory  vessels  appear  in  the  medullary 
parenchyma  mth  diameters  ranging  from  29  to  63,a.  Fuhrmann  gave  24  as 
the  number,  while  Solowiow  gave  their  size  as  13.9  to  23.3/i.  Foramina  secun- 
daria pierce  the  cuticula  here  and  there,  but  they  are  not  very  numerous. 

As  indicated  in  the  diagnosis  of  the  subfamily  the  reproductive  organs 
appear  close  behind  the  scolex.  In  one  toto  preparation  of  a  larval  specimen, 
number  72  of  the  above  table,  the  earliest  traces  of  their  rudiments  were  present 
in  the  18th  proglottis,  or  3.96mm.  from  the  anterior  end,  while  in  the  only 
mature  specimen,  H.7,  they  were  in  the  16th  proglottis,  a  few  eggs  appearing 
in  the  uterus  of  the  17th.  The  cirrus  and  vagina  open  close  together  in  a 
very  shallow  and  sometimes  quite  obliterated  genital  cloaca  having  a  maximum 
diam.eter  of  about  90ju,  the  vagina  behind  the  cirrus,  but  only  very  slightly 
either  to  the  right  or  left  and  not  according  as  the  uterine  opening  further 
back  Ukewise  alternates  irregularly  but  with  a  greater  ampUtude.  The  three 
apertures  form  almost  a  right-angled  triangle,  as  described  by  Kiessling;  but, 
as  was  pointed  out  by  Luhe  (1899a  :716)  this  arrangement  is  by  no  means  con- 
stant but  varies  with  the  state  of  contraction  or  relaxation  of  the  whole  "itrobila 
and  hence  cannot  be  considered  as  specific. 

The  testes  are  arranged  in  a  single  layer  in  the  dorsal  portion  of  the  medulla 
not  only  in  the  larva  but  also  in  the  adult,  as  described  by  Fuhrmann,  the 
majority  of  the  excretory  vessels  being  situated  tov/ards  the  ventral  side  of  the 


38  ILUNOIS  BIOLOGICAL  MONOGRAPHS  [326 

medulla.  They  axe  absolutely  continuous  from  proglottis  to  proglottis.  Their 
number  in  transections  is  from  30  to  40  (30  to  35,  Kiessling)  and  in  sagittal 
sections  from  8  to  12  for  each  proglottis,  thus  making  the  total  from  240  to  480 
or  over  300  on  the  average,  which  stands  in  distinct  contrast  with  the  number 
of  about  100  given  by  Fuhrmann.  The  latter  also  gave  their  dimensions  as  80 
by  34/i,  Kiessling  as  16  to  ttn  in  young  and  149/1  in  mature  animals,  and  Solo- 
wiow  as  68  to  93ju.  The  writer  found  them  to  be  from  85  to  100/x  in  depth,  40  to 
65/i  in  width  and  55  to  85/*  in  diameter.  They  are,  as  indicated  by  their  num- 
bers, very  closely  crowded  together  in  the  proglottis.  The  vas  deferens  forms 
a  compact  mass  of  coils  situated  in  the  median  line  dorsally  and  shghtly  pos- 
terior to  the  vesicula  seminalis  to  which  it  is  closely  applied  as  a  sort  of  cap. 
While  the  diameter  of  the  whole  organ  is  about  0.3mm.  that  of  the  duct  itself 
varies  from  35  to  60)u  when  distended  with  spermatozoa.  Kiessling  gave  its 
diameter  as  38/i  and  Solowiow  as  16.3/i.  The  large  thick-walled  seminal  vesicle 
(Fig.  80)  situated  immediately  above  the  cirrus-sac  was  f  oimd  to  have  a  maxi- 
mum depth  of  175/1  and  transverse  diameter  of  150/i,  as  compared  with  the 
92/i  of  Kiessling  and  the  80/x  of  Fuhrmann.  Its  walls  are  very  muscular,  about 
25/1  in  greatest  thickness,  and  covered  both  internally  and  externally  \%ath 
numerous  nuclei  which  are  respectively  epithelial  and  parenchymatous  or 
myoblastic  in  their  nature.  Within  the  cirrus-sac  the  vas  deferens  is  much 
coiled  but  not  enlarged  to  form  any  secondary  vesicle  nor  sharply  separated 
into  an  ejaculatory  duct  and  cirrus  proper.  The  sac  itself  is  oval  in  shape, 
the  ventral  end  being  the  smaller,  and  the  proximal  end  somewhat  invaginated 
by  the  seminal  vesicle.    Its  size  is  shown  in  the  following  table: 


KTESSLIKG 

FUHRMANN 

SOLOWIOW 

THE  WRITER 

Depth 

0.347mm. 

0.25mm. 

0.204mm. 

0.185  to  0.203mm. 

Width 

0.192mm. 

0.12mm. 

0.174mm. 

0.203  to  0.212mm. 

Length 

0.166  to  0.185mm. 

Its  wall  about  equal  in  thickness  to  that  of  the  seminal  vesicle  is,  however,  more 
open  in  texture,  the  myoblastic  nuclei  of  the  obliquely  arranged  muscle  fibres 
being  scattered  thruout  its  diameter  (Fig.  80).  It  is  furthermore,  not  sharply 
separated  either  externally  or  internally  from  the  surrounding  parenchyma 
nor  the  numerous  stout  retractor  muscles  of  the  cirrus,  respectively.  The 
latter,  in  fact,  constitute  practically  the  whole  of  the  contents  of  the  sac  apart 
from  the  duct  itself.  The  only  protruded  cirrus  seen  had  a  length  of  70/t,  as 
compared  mth  the  0.3945mm.  given  by  Solowiow. 

The  vagina,  the  opening  of  which  is  usually  situated  about  50/i  from  that 
of  the  cirrus  at  the  bottom  of  the  shallow  genital  cloaca  above  mentioned,  has 
a  diameter  of  from  45  to  60/t  at  the  first  bend  in  its  course  within  the  medullary 
parenchyma.  Soon  after  it  enters  the  latter  it  becomes  thin-walled,  as  pointed 
out  by  Fuhrmann,  owing  to  the  thiiming  out  of  the  cuticula  and  the  substitu- 
tion of  the  proximal  nucleated  epithelium  for  the  same,  altho  more  peripherally 
much  flattened  nuclei  are  to  be  seen  beneath  the  cuticula  and  crowded  close 
to  the  basement  membrane.    In  other  words  the  gradual  replacement  from 


3271  PSEUDOPHYLLIDEA  FROM  FISHES— COOPER  39 

within  outwards  of  the  cuticula  for  the  original  epithelium  may  be  followed 
very  easily  in  the  walls  of  the  vagina.  The  duct  gradually  enlarges  to  form 
a  much  elongated  receptaculum  seminis  (Fig.  79)  with  a  diameter  of  92  to  104/i 
(9  to  21)u,  according  to  Kiessling!)  and  sharply  separated  from  the  spermiduct, 
which,  however,  was  not  found  to  unite  with  the  oviduct  close  to  the  dorsal 
transverse  musculature  as  stated  by  Fuhrmann,  but  close  to  the  ventral  wall 
of  the  medulla.  The  ovary  consists  of  two  large  wings  (Fig.  79),  composed  of 
closely  crowded  tubules,  lying  immediately  upon  the  ventral  transverse  muscles 
and  united  by  a  much  smaller  isthmus,  the  whole  having  a  width  of  0.64mm.  as 
compared  with  the  0.28mm.  of  Solowiow.  The  average  length  and  depth  of 
the  wings  are,  respectively,  105  and  90/i.  Ova  from  the  isthmus  and  more 
median  portions  of  the  "vsdngs  of  the  ovary  have  a  diameter  of  13n  while  their 
nuclei  are  5/x.  The  respective  measurements  by  Kiessling  and  Solowiow  are 
9  and  6ju  and  13.9  to  23.3jLt  and  1.5  to  2/x.  Fuhrmann  stated  that  one  of  the  most 
important  differences  between  his  Sch.  zschokkei  and  Sch.  solidus  was  the  pre- 
sence in  the  former  of  an  oocapt,  but  Luhe  (1899a  :7 17)  claimed  that  this 
structure  was  in  all  probability  overlooked  by  Kiesshng.  It  arises  from  the 
posterior  aspect  of  the  isthmus  almost  in  the  median  Hne  with  a  diameter  of 
from  35  to  40;ii.  The  oviduct,  according  to  Kiessling  has  a  diameter  of  13,  or 
to  Solowiow  of  27ju;  here  it  was  found  to  be  from  25  to  30/i  between  the  entrance 
of  the  vagina  and  that  of  the  common  vitelline  duct,  which  two  points  are  close 
together  as  in  L.  intestinalis.  The  common  vitelline  duct  enlarges  some  Uttle 
distance  from  its  opening  into  the  oviduct  to  form  a  vitelUne  reservoir  having 
a  diameter  of  30)Li  (23/^,  Kiessling).  The  vitelline  follicles  are  extremely  num- 
erous and  closely  crowded  together  in  a  layer  with  a  maximum  thickness  of 
85/i,  situated  between  the  inner  longitudinal  and  middle  transverse  muscles 
(Fig.  79).  They  are  continuous  at  the  margins  of  the  proglottis  as  they  are 
from  joint  to  joint,  and  are  broken  only  in  Hmited  elliptical  areas  above  and 
below  the  reproductive  ducts  in  the  median  line,  as  stated  by  Fuhrmann. 
The  dimensions  of  the  individual  follicles  are  from  58  to  87  by  18  to  26/li, 
the  larger  dimensions  being  the  dorsoventral  diameters, — 56  to  107  by  56/i,  ac- 
cording to  Kiessling,  and  18  by  21  y.  after  Solowiow.  Just  beyond  the  entrance 
of  the  common  vitelUne  duct  the  oviduct  enlarges  to  form  the  ootype  with 
a  diameter  of  16/Li  (20jLt,  Kiessling)  which  is  surrounded  by  the  shell-gland, 
situated  just  above  the  median  frontal  plane  and  somewhat  lateral.  Thru- 
out  its  course  the  oviduct  is  lined  with  an  epithelium  in  which  prominent 
nuclei  but  no  distinct  cell  boundaries  appear  and  from  which  numerous  cilia 
protrude  into  the  lumen.  In  the  ootype  these  cilia  are  much  more  noticeable. 
From  the  ootype  the  oviduct  passes  ventrally  with  a  few  coils,  then  across  the 
median  line  close  above  the  receptaculum  seminis  as  the  beginning  of  the 
uterus.  The  latter  gradually  enlarges  as  it  passes  forward  across  the  median 
line  several  times,  until  at  about  the  middle  of  its  course  it  has  a  diameter 
of  85  to  135)U.  As  regards  the  terminal  portion  of  the  tube  it  was  found  that, 
as  Fuhrmann  observed:  "Der  Endtheil  der  Uterus  verengert  sich  und  ver- 
laiift  von  der  Dorsalflache  [the  median  frontal  plane  in  which  the  last  trans- 


40  ILLINOIS  BIOLOGICAL  MONOGRAPHS  [328 

verse  coil  is  situated]  direkt  ventral,  um  regelmassig  abwechselnd  links  oder 
rechts  neben  der  Vagina  auszumiinden. " 

Sections  show  that  the  actual  opening  is  formed  by  the  rupture  of  the  bot- 
tom of  a  cup-like  invagination  of  the  cuticula  from  the  ventral  surface,  which 
meets  the  end  of  the  duct  with  a  diameter  of  from  25  to  40/x.  As  Fuhrmann 
stated,  "Dieser  Ausfuhrgang  der  Uterus  ist  von  der  Stelle  an,  wo  er  ins  Rinden- 
parenchym  tritt,  wie  die  Vagina  und  der  Cirrusbeutel,  von  zahlreichen  Paren- 
chymmuskeln  umhiillt  und  von  einer  der  Korpercuticula  ahnlichen  Membran 
ausgekleidet;"  but  the  cuticula  seems  to  appear  as  such  only  near  the  opening, 
since  only  half-way  back  along  this  dorsoventral  limb  of  the  organ  flattened 
nuclei  are  distinctly  seen.  In  other  words  the  flattened  epithelium  of  the 
uterus,  which,  showing  only  a  few  scattered  nuclei,  was  described  by  Kiessling 
as  a  "fine,  structureless  but  elastic  membrane,"  passes  insensibly  into  the 
cuticula  near  the  opening,  no  distinct  line  of  junction  between  the  two  being 
discernible.  This  latter  statement  is  likewise  applicable  to  the  similar  struc- 
ture of  the  vagina. 

The  dimensions  of  the  ellipsoidal  eggs  in  the  sections  of  the  uterus  were 
found  to  be  62  to  65  by  33  to  36/x.  Kiessling  gave  them  as  49  by  37^  and 
Fuhrmann  as  70  by  29jli.  In  discussing  the  latter,  however,  Liihe  (1899a:718) 
remarked  that  not  only  did  he  find  variations  from  38  by  22  to  56  by  38/i  in 
the  size  of  the  eggs  in  material  of  B.  zschokkei  sent  to  him  by  Fuhrmann,  but 
that  in  general  even  greater  variations  than  these  are  to  be  found  in  other  spe- 
cies according  to  the  various  writers. 

Our  knowledge  of  the  life-history  of  this  species  dates  from  the  time  of 
Abildgaard  (1790)  who,  as  mentioned  above,  was  the  first  to  experiment  with 
the  larval  individuals  found  in  fishes.  Creplin  (1829)  united  the  two  forms 
which  were  considered  to  be  two  separate  species  into  one  species,  evidently 
on  the  basis  of  the  previous  work,  especially  Abildgaard's  (cf.  Donnadieu, 
1877:340),  while  Donnadieu  in  his  elaborate  experiments  on  the  life  history 
of  Ligula  unfortunately  did  not  differentiate  between  it  and  Schistocephalus. 
The  development  of  the  fertilized  embryo  into  the  oncosphere  was  first  studied 
by  Willemoes-Suhm  (1869)  and  later  more  in  detail  by  Schauinsland  (1885:555), 
since  when  nothing  of  special  importance  has  been  added,  so  far  as  the  writer 
is  aware.  Hence  up  to  the  present  nothing  is  known  about  the  development 
of  the  oncosphere  into  the  larva  in  the  intermediate  host,  as  is  indeed  the  case 
with  most  of  the  bothriocephalids. 

As  regards  the  identity  of  the  material  studied  with  the  European  species 
it  will  be  seen  from  the  above  comparisons  that,  while  there  are  many  dis- 
crepancies among  the  data  given  by  Kiessling,  Fuhrmann  and  Solowiow,  those 
by  the  latter  departing  the  farthest  in  many  respects,  the  resemblances  so  out- 
weigh the  differences  as  to  make  the  erection  of  a  new  species  unjustifiable. 
The  thickness  of  the  cuticula,  the  diameter  of  the  excretory  vessels,  the  dimen- 
sions of  the  seminal  vesicle,  the  ovary  and  the  eggs,  which  constitute  the 
majority  of  the  differences,  might  easily  be  explained  by  differences  in  age  of 
the  material  studied.    But  the  number  of  testes  (100)  as  given  by  Fuhrmann 


329]  PSEUDOPHYLLIDEA  FROM  FISHES— COOPER  41 

can  scarcely  be  reconciled  with  that  given  here  (300+ ),  altho  his  dimensions 
of  the  organs  agree  with  these  perhaps  better  than  do  those  by  Kiessling  or 
Solowiow.  On  the  other  hand  there  is  another  factor  which  may  be  in  the  long 
run  more  important  than  a  comparison  of  the  details  of  the  anatomy  of  this 
evidently  highly  variable  species,  namely,  the  geographical  distribution  of  the 
hosts.  Altho  little  emphasis  can  be  placed  on  Fabricius'  finding  T.  gasterostei 
in  the  type  larval  host  as  long  ago  as  1780  in  Greenland,  it  must  be  remembered 
that  here  in  America  there  are,  as  in  the  case  of  L.  intestinalis,  a  number  of  not 
only  the  same  genera  but  also  of  the  same  species  of  the  larval  as  well  as  of  the 
adult  hosts  as  in  Europe.  From  this  alone  one  would  be  justified  in  expecting 
to  find  the  same  species  of  Schistocephalus  here,  especially  since  it  infests  such 
a  number  of  different  host  species.  But  it  is  a  very  surprising  fact  that  apart 
from  Linton's  report  of  the  larva  from  Montana  evidently  no  one  has  up  to 
the  present  found  the  form  in  any  of  the  numerous  fish-eating  birds  of  the 
continent. 

This  evident  infrequent  occurrence  of  the  species  is  illustrated  by  the  fact 
that  the  material  used  for  the  present  study  consisted  of  only  five  lots:  Nos. 
61b  and  72  from  the  body  cavities  of  Uranideaformosa,  taken  from  the  stomach 
of  Lota  maculosa,  and  190  from  the  coelom  of  Gasterosteus  bispinosus  atkinsii, 
of  the  writer's  collection;  one  lot  from  Gasterosteus  cataphr actus  from  Alaska; 
and  No.  17.192  of  the  collection  of  the  University  of  Illinois  from  the  intestine 
of  Lophodytes  cucullatus,  the  only  mature  specimen  available. 


42  ILLINOIS  BIOLOGICAL  MONOGRAPHS  [330 


HAPLOBOTHRIINAE  Cooper  1917 

Strobila  formed  by  the  subdivision  of  the  segments  of  a  primary  strobila. 
Scolex  of  the  latter  a  cylindrical,  somewhat  club-shaped  organ  bearing  four 
eversible  proboscides  similar  in  structure  to  those  of  the  Trypanorhyncha ; 
scolex  of  the  secondary  (definitive)  strobila  merely  the  shghtly  modified  fore- 
most segment,  provided  with  shallow  dorsoventral  depressions  analogous  to 
the  bothria  of  other  bothriocephalids.  An  elongated  neck  may  be  said  to  be 
present  in  the  primary  strobila.  Segmentation  of  the  primary  strobila  result- 
ing in  the  formation  some  distance  behind  the  scolex  of  a  comparatively  small 
number  of  long,  narrow  segments  which  in  turn  subdivide  anteriorly  to  form 
the  segments  of  the  secondary  strobila.  Segmentation  in  the  latter  thus 
beginning  immediately  behind  the  secondary  scolex,  but  complete  in  its  anterior 
region  only.  Genital  organs  simple  in  each  proglottis.  Genital  openings 
surficial,  ventral  and  median  as  in  the  Diphyllobothriinae.  Ovary  and  shell- 
gland  median,  respectively  ventral  and  dorsal.  Vitelline  folUcles  in  the  medul- 
lary parenchyma,  as  are  the  testes,  both  within  the  nerve  trunks.  Testes 
separated  into  two  lateral  fields  by  the  median  excretory  vessel  and  the  genital 
organs  in  the  median  line.  Vas  deferens  enlarged  to  form  a  large  non-muscular 
seminal  vesicle  before  entering  the  cirrus-sac.  Cirrus  armed  with  minute 
spines.  Receptaculum  seminis  medium  sized,  sharply  separated  from  the 
spermiduct.  Uterus  divided  into  a  much  coiled,  proximal  uterine  duct  and  a 
large  uterus-sac,  as  in  the  Ptychobothriidae. 

Tj'pe  genus:  Haplobothrium  Cooper. 

Altho  as  yet  comparatively  little  is  known  about  the  life-histories  of  the 
bothriocephaHds,  it  has  been  shown  that  the  definitive  scolex  and  strobila 
develop  directly  from  the  larval  stage,  known  as  the  plerocercoid,  which  is 
present  in  the  intermediate  host.  This  is  certainly  the "  case  with  Ligula, 
Schistocephalus,  Diphyllobotkrium  latum,  Cyathocephalus  truncatus  and  Tri- 
aenophorus.  As  a  matter  of  fact  in  all  of  these  the  scolex  is  more  or  less  well 
formed  before  the  larva  reaches  the  final  host;  and  after  that  the  plerocercoid 
continues  to  grow  and  soon  shows  the  beginnings  of  segmentation  which  mark 
the  young  strobila.  Consequently  the  wTiter  feels  that  what  in  the  present 
paper  is  called  the  primary'  strobila  of  Haplobothrium  must  be  looked  upon  as 
the  true  strobila,  homologous  to  the  young  strobila  of  other  bothriocephalids. 
This  is  contended  in  spite  of  the  fact  that  what  was  formerly  considered 
(Cooper,  1914, 1914a)  to  be  the  strobila  is  quite  similar,  apart  from  the  absence 
of  external  segmentation  in  its  posterior  region,  to  that  of  other  members  of 
the  order.  Even  tho  it  is  provided  with  a  very  aberrant  scolex  region — and 
the  scolex  is  no  more  sharply  set  off  from  the  rest  of  the  larva  in  other  species, 
such  as  D.  latum — the  young  imsegmented  primary  strobila  may  be  considered 
to  be  a  typical  plerocercoid. 

The  nervous  system  is  typical  in  that  it  consists  of  two  chief  strands  united 
anteriorly  by  a  commissure.    The  relatively  large  size  of  the  latter,  however, 


331]  PSEUDOPHYLLIDEA  FROM  FISHES— COOPER  43 

seems  to  be  due  to  the  proximity  of  the  highly  specialized  proboscides  to  which 
it  sends  large  branches.  The  excretory  system  is  likewise  built  on  the  typical 
plan,  the  posterior  connections  with  the  exterior  being,  in  fact,  quite  like  those 
of  B.  scorpii.  On  the  other  hand,  the  terminations  of  the  nervous  and  excretory 
systems  in  the  secondary  strobila,  both  anteriorly  and  posteriorly  support  the 
view  that  the  latter  is  not  homologous  with  the  strobila  of  other  bothriocepha- 
lids.  What  was  formerly  described  as  the  ring  commissure  must  now  be  con- 
sidered as  merely  a  secondary  formation  due  to  the  fusion  of  the  severed  ends 
of  the  chief  strands;  which  statement  is  also  applicable  to  the  terminal  vesicle 
of  the  excretory  system.  And  this,  in  spite  of  the  fact  that  the  secondary  scolex 
is  quite  similar  to  the  true  scolex  of  other  forms  in  that  it  is  supplied  with  two 
sets  of  muscles  which  are  not  foimd  in  the  foremost  segments,  but  are  peculiar 
to  the  scolex. 

Since  there  is  considerable  evidence  in  the  literatm-e  on  cestodes  to  show 
that  the  prominent  posterior  borders  of  the  foremost  segments  of  many  species 
are  developed  as  accessory  organs  of  attachment  or  for  locomotion  (cf .  Spengel, 
1905:281),  the  question  might  well  be  raised  whether  external  segmentation 
in  Haplobothrium  is  palingenetic  or  cenogenetic  in  its  nature,  particularly 
since  it  is  confined  to  the  anterior  region  of  the  secondary  strobila.  The  facts 
that  no  such  appendages  are  present  in  the  primary  strobila  and  that  the 
posterior  end  of  the  secondary  one  is  not  segmented,  apart  from  the  consecutive 
sets  of  genitalia,  would  seem  to  point  to  the  original  condition  being  one  in 
which  external  segmentation  was  absent  as  in  Ligula  or  Triaenophorus.  Since, 
however,  in  the  middle  region  of  the  secondary  strobila  there  is  an  actual 
correspondence  between  the  external  and  the  internal  segments,  it  is  quite 
probable  that  the  external  segmentation  is  much  older  than  might  at  first 
appear,  while  the  hgulate  condition  of  the  posterior  end  may  have  developed 
secondarily.  It  is  well  to  remember,  too,  in  this  connection  that  according  to 
Liihe  (1898:285)  Ligula  has  descended  from  fully  segmented  bothriocephalids. 

The  subfamily,  which  up  to  the  present  contains  only  one  genus  and  one 
species,  bears  a  general  resemblance  to  the  Diphyllobothriinae.  It  differs 
from  the  latter,  however,  in  that  the  genital  organs  are  simple  in  each  proglottis; 
the  vitelline  folhcles  are  medullary;  the  testes  are  within  (i.e.,  medial  to)  the 
nerve  trunks;  the  seminal  vesicle  is  not  strongly  muscular;  the  cirrus  is  armed 
with  minute  spines;  the  receptaculum  seminis  is  medium  sized;  while  the  uterus 
is  divided  into  a  uterine  duct  and  uterus-sac  as  in  the  Ptychobothriidae. 

HAPLOBOTHRIUM  Cooper  1914,  e.  p. 

Haplobothrium  Cooper  1914:1-2,    1914a:115 

Borders  of  the  terminal  disc  of  the  secondary  scolex  and  of  the  posterior 
auricular  appendages  of  both  scolex  and  anterior  segments  provided  with  min- 
ute spines  which  disappear  with  the  appendages  farther  back.  Nervous  system 
consists  of  two  chief  strands  situated  in  the  medullary  parenchyma  outside  of 
the  viteUine  follicles,  uniting  in  the  anterior  end  of  the  secondary  strobila  to 
form  a  secondary  nerve  ring,  and  eight  collateral  strands,  four  arranged  around 


44  ILLINOIS  BIOLOGICAL  MONOGRAPHS  [3^2 

each  main  tract,  the  latter  in  the  jointed  portion  of  the  strobila  only,  but  in  the 
true  scolex  to  form  an  irregular  transverse  commissure  situated  among  the  pro- 
boscides.  Excretory  system  composed  of  one  large  median  and  slightly  dorsal 
vessel  and  two  smaller  lateral  and  ventral,  all  uniting  in  the  secondary  scolex 
behind  the  nerve  ring  to  form  a  vesicle.  No  genital  cloaca;  opening  of  vagina 
close  behind  that  of  cirrus,  towards  the  anterior  end  of  the  proglottis,  that  of 
the  uterus  much  farther  back.  Sphincter  vaginae  present.  Vitelline  glands 
in  numerous  follicles  arranged  cylindrically  around  the  testes,  both  continuous 
from  proglottis  to  proglottis,  leaving  clear  areas  opposite  the  central  genital 
ducts;  large  vitelline  reservoir.  Vas  deferens  provided  with  a  sperm-reservoir 
at  its  posterior  end  near  the  middle  of  the  proglottis;  whole  of  the  course  of  the 
duct  dorsal  to  the  uterus-sac.  Uterus-sac  when  gravid  occupies  the  whole  of 
the  middle  of  the  proglottis. 

Type  and  only  species:  H.  globuliforme  Cooper. 

The  genus  is  here  emended  owing  to  the  elevarion  to  subfamily  rank  of  a 
number  of  the  characters  given  in  m}^  original  generic  description. 


HAPLOBOTHRIUM  GLOBULIFORME  Cooper  1914 
[Figures  9,  10,  43,  44,  65-67] 
1914        Haplobothrium  globuliforme  Cooper  1914:2,  1914a:l  15 

Specific  diagnosis:  With  the  characters  of  the  genus.  Small  worms,  pri- 
mary strobila  up  to  70mm.  in  length,  secondary  to  110mm.,  with  respective 
maximum  breadths  of  0.3  and  0.6mm.  Primary  scolex  0.35mm.  in  diameter, 
indefinite  in  length,  bulbs  0.40  to  0.45  by  0.06  to  0.07mm.;  secondary  scolex, 
0.4  to  0.5  by  0.25  to  0.4mm.  Auricular  appendages  disappear  at  about  the  25th 
segment  in  normal  secondary  strobilas.  Foremost  secondary  segments  tet- 
ragonal, middle  and  posterior  much  elongated  and  considerably  depressed. 

Cuticula  3  to  4;u  in  thickness,  subcuticula  25;U.  Chief  nerve  strands  18pi  in 
diameter,  narrowing  intersegmentally.  Terminal  excretory  vesicle  20  to  40/i 
in  diameter. 

Genital  organs  begin  at  about  the  15th  proglottis.  Opening  of  cirrus  and 
vagina  0.02  to  0.07nim.  apart. 

Testes  spherical  to  ellipsoidal  in  shape,  70  to  115/x  in  maximum  length; 
about  80  in  each  segment.  Vas  deferens  median,  elongated,  only  slightly 
coiled,  10  to  55ai  in  diameter.  Vesicula  seminalis  broadly  spindle-shaped,  140 
by  90)u.  Cirrus  20  to  30ai  in  diameter;  cirrus-sac,  0.16  to  0.21  by  0.14  to  0.16 
by  0.18  to  0.20mm. 

Vagina  20  to  30/x  in  diameter  at  its  opening,  56/x  in  its  enlarged  distal  por- 
tion. Receptaculum  seminis  30  to  45/Li  in  diameter,  spermiduct  5  to  10)u  and 
very  muscular.  Ovary  hippocrepiform,  the  Umbs  directed  posteriorly  and 
often  fused  with  each  other,  the  isthmus  narrow.  Ova  from  latter  10  to  12;* 
in  diameter,  their  nuclei,  7/x.    Oocapt  15  to  25^  in  diameter,  oviduct  8  to  15;i. 


333] 


PSEUDOPHYLLIDEA  FROM  FISHES— COOPER 


45 


Two  vitelline  ducts,  each  6ju  in  diameter;  vitelline  reservoir  25  to  55/*;  follicles 
spherical  or  elUpsoidal  in  shape,  8  to  SOfx.  in  diameter,  very  nimierous  and  closely 
crowded.  Ootype  20/i  in  diameter;  shell-gland  irregular  in  shape,  poorly 
developed.  Uterine  duct  enlarged  proximally  with  few  coils,  smaller  distally 
and  more  coiled,  median,  25  to  55/x  in  diameter;  uterus-sac  elongated,  filling 
most  of  the  medulla  when  gravid;  uterus  opening  a  small  median  elongated  slit, 
situated  near  the  posterior  end  of  the  sac. 

Eggs,  60  to  70  by  40  to  43^. 

Habitat:  In  the  intestine  of  Amia  calva  L. 


HOST 

LOCALITY 

COLLECTOR 

AUTHORITY 

Amia  calva  L. 

(type  host) 
)>        )> 

Go -Home  Bay, 
Muskoka,  Ontario 
Havana,  Illinois 

Fairport,  Iowa 

A.  R.  Cooper 
H.  B.  Ward 

Cooper         19Ua:81 

Cooper  (the  present 

paper) 
>> 

T3T)e  specimen:  No  33.1  in  the  writer's  collection. 

Co-types:  Nos.  33.2  and  33.3  of  the  same,  in  the  collection  of  the  University  of  Illinois 

In  a  preHminary  paper  on  the  systematic  position  of  this  species  the  writer 
(1914:1)  described  the  scolex  as  ".  .  .  unarmed,  although  the  edges  of  the 
terminal  disc  and  auricular  appendages  of  both  scolex  and  anterior  proglottides 
are  provided  with  very  minute  spines.  Bothria,  two  shallow  depressions  on 
the  dorsal  and  ventral  surfaces,  very  simple  in  structure, "  and  In  the  detailed 
description  which  followed  (1914a)  the  organ  was  dealt  with  as  follows  (p.  82): 
"The  scolex  is  quite  small,  simple  externally,  and  with  the  unaided  eye  can 
scarcely  be  distinguished  from  the  first  joints.  It  is  shaped  roughly  like  a 
rectangular  solid,  hollowed  out  laterally  to  form  simple  depressions  and  dorso- 
ventrally  the  shallow  bothria  or  organs  of  attachment.  The  summit  is  some- 
what prolonged  as  a  low  pyramidally-shaped  disc,  quite  comparable  to  that 
("Scheitelplatte")  found  in  the  members  of  the  subfamily  Triaenophorinae 
Luhe  1899.  .  .  .  The  opposite  end  of  the  scolex  is  modified  to  form  two 
pairs  of  auricular  appendages  closely  resembling  internally  as  well  as  externally 
those  of  the  foremost  joints. "  Furthermore,  in  both  papers  it  was  emphasized 
that  the  scolex  differs  little  in  structure,  apart  from  the  nervous  and  excretory 
systems,  from  the  first  segments,  and  that  the  simple  bothria  seem  of  little 
fimctional  importance  as  compared  to  those  of  other  species  while  the  auricular 
appendages  of  both  scolex  and  foremost  joints  with  their  borders  of  minute 
cuticular  spines  probably  act  as  accessory  organs  of  attachment.  Since  then 
the  latter  view  has  been  rendered  still  more  highly  probable,  altho  as  yet  no 
observations  have  been  made  on  the  living  worms  in  their  relation  to  the  wall 
of  the  host's  intestine,  by  the  discovery  that  the  so-called  scolex  (Figs.  9  and 
10)  is  not  in  reality  the  scolex  but  only  a  slightly  modified  anterior  segment. 

The  true  scolex  is  somethmg  quite  different  from  anything  present  in  the 
whole  order  so  far  as  the  writer  is  aware.    As  shown  in  figures  43,  and  44,  it  con- 


46  ILLINOIS  BIOLOGICAL  MONOGRAPHS  [334 

sists  of  the  slightly  enlarged  anterior  end  of  the  original  plerocercoid  or  larva 
from  which  protrude  four  proboscides,  the  whole  somewhat  resembling  a  hydra 
and  at  once  reminding  one  of  the  Trypanorhyncha.  As  will  be  presently  seen 
the  latter  comparison  is  a  very  apt  one.  Each  proboscis  consists  of  a  per- 
manently protruded  base  or  stump,  as  indicated  in  figure  43,  about  85m  in 
length  and  45  to  SSn  in  diameter,  and  an  eversible  proboscis  proper  having 
about  the  same  diameter.  The  former  is  somewhat  conical  in  shape  and  thickly 
set  with  minute,  posteriorly  directed  cuticular  spines  which  pass  on  to  the 
neighboring  portions  of  the  scolex  for  a  short  distance.  The  whole  forms  at 
first  sight  a  continuous  tentacle  gradually  diminishing  in  size  to  the  pointed 
end.  These  tentacles  attain  a  length  of  0.35mm.,  including  the  base,  when 
fully  evaginated,  and  are  directed  almost  at  right  angles  to  the  longitudinal 
axis  of  the  larva,  their  bases  being,  however,  turned  slightly  forward  (Fig.  43). 
Within  the  scolex  the  tentacles  are  accommodated  in  elongated  cyUndrical 
muscular  sacs  which  are  quite  comparable  in  structure  to  the  bulbs  of  the 
Trypanorhyncha.  These  (the  sacs)  lie  freely  in  the  loose  parenchymatous 
tissue  in  the  diagonal  diameters  of  the  region.  When  the  proboscides  are 
invaginated,  they  have  a  length  of  0.45mm.  with  a  diameter  of  0.07,  or  0.40 
by  0.06  when  the  tentacles  are  protruded.  The  walls  of  the  bulb  (Fig.  67)  are 
composed  of  two  thick  layers  of  muscles,  an  outer  longitudinal  or  somewhat 
obUque — much  the  heavier  of  the  two — and  an  inner  circular,  and  a  cuticula- 
like  lining,  on  the  inner  border  of  which  in  transections  numerous  flattened 
nuclei  appear.  The  walls  are  attached  to  the  edge  of  the  stump,  and  these 
layers  have  the  same  relative  arrangement  as  that  of  the  cuticula  and  cuticular 
muscles  on  the  outside  of  the  body,  only  being  in  the  reverse  order.  Con- 
tinuous also  with  the  edge  of  the  stumps  are  the  walls  of  the  proboscis  proper, 
which  consist  of  a  thin  external  layer  of  cuticula  and  only  feeble  cuticular  mus- 
cles. Attached  to  the  wall  internally  thruout  its  course  are  the  retractor  mus- 
cles of  the  proboscis  which  pass  backward  and  become  attached  to  the  posterior 
end  of  the  bulb.  These  can  be  seen  best  in  longitudinal  sections  where  the 
proboscis  is  retracted,  for  then  they  are  closely  crowded  and  much  thicker,  and 
their  attachment  to  the  inner  end  of  the  proboscis  is  nicely  shown.  In  the 
retracted  condition  the  latter  is,  of  coiu-se,  hollow,  the  narrow  cavity  often 
triradiate  in  transection  (Fig.  67)  being  easily  followed  into  the  bulb  for  about 
one-third  of  its  length.  Closely  appHed  to  the  cuticula  of  the  tip  of  the  pro- 
boscis appear  in  some  cases  gland-like  cells  taking  the  counterstain  quite  like 
those  behind  the  bulbs  to  be  described  below.  They  are  shown  in  figure  67. 
Apart  from  the  structures  aheady  described,  the  contents  of  the  bulbs  and 
consequently  of  the  proboscides  to  a  certain  extent,  consist  of  a  small  amount 
of  loose  parenchymatous  tissue  and  what  is  evidently  a  good  deal  of  nervous 
tissue  coming  into  the  Dostennr  end  of  the  organ. 

Evagination  of  the  proboscides  is  evidently  brought  about  by  the  contrac- 
tion of  the  muscles  in  the  walls  of  the  bulbs,  but  the  body  wall  in  the  vicinity 
of  the  latter  probably  greatly  assists  since  its  musculature  is  well  developed. 
Some  distance  behind  the  posterior  ends  of  the  bulbs  the  latter  consists  of  a 


335]  PSEUDOPHYLLIDEA  FROM  FISHES— COOPER  47 

ring-like  layer  of  loosely  arranged  main  longitudinal  fibres  occupying  the 
middle  one-third  of  the  radius  of  the  nearly  circular  cross-section;  no  trans- 
verse fibres;  but  comparatively  strong  cuticular  muscles,  of  which  the  inner 
longitudinal  layer  is  the  more  pronounced.  Farther  forward  this  main  longi- 
tudinal group  gradually  gives  off  small  fibres  towards  the  cuticula  as  they  them- 
selves diminish  in  number  and  size,  until  at  the  level  of  the  hinder  ends  of  the 
bulbs  only  a  few  of  the  latter  fibres  are  left  jilst  beneath  the  subcuticula.  An 
outer  series  at  the  same  time  forms  a  compact  layer  situated  close  to  the  longi- 
tudinal cuticular  fibres  (and  hence  outside  of  the  subcuticular  nuclei)  but 
separated  from  them  by  a  thin  stratum  of  circular  fibres.  And  this  continues 
to  the  tip  of  the  scolex,  most  of  the  remaining  inner  longitudinal  muscles  being 
located  at  the  ends  of  the  transverse  and  dorsoventral  diameters  of  the  transec- 
tion. In  the  region  of  the  bulbs  the  body  wall  is  thus  quite  muscular,  and  in 
all  probability  assists  the  bulbs  in  evaginating  the  proboscides  by  compressing 
the  whole  of  the  parenchyma  slirrounding  them.  Between  the  bulbs  and  right 
beneath  the  tip  of  the  scolex  a  few  transverse  and  sagittal  fibres  are  to  be  found, 
while  just  beneath  the  bases  of  the  stumps  of  the  proboscides  the  outer  longi- 
tudmal  muscles  unite  with  the  longitudinal  cuticular  fibres  to  form  fl-shaped 
loops  surrounding  the  diagonal  quadrants  of  the  scolex  which  accommodate 
the  bulbs.  These  loops  are  evidently  for  the  control  of  the  direction  of  the 
proboscis  stumps. 

Owing  to  the  fact  that,  as  originally  stated  by  the  writer  (1914a:96),  "there 
is  a  more  or  less  definite  point  in  the  strobila,  at  or  about  the  15th  proglottis, 
ahead  of  which  the  genital  organs  do  not  seem  to  develop  and  behind  which 
in  older  strobilas  they  appear  very  quickly, "  and  the  further  fact  that  not  only 
do  the  auricular  appendages  of  the  posterior  ends  of  the  proglottides  disappear 
at  about  the  same  place  constantly,  namely,  at  about  the  23rd  or  24th  segment, 
it  might  seem  that  the  (secondary)  strobila  is  composed  of  a  more  or  less 
definite  and  predetermined  number  of  segments.  But  this  is  not  the  case, 
as  will  be  seen  presently  when  the  method  of  formation  of  new  proglottides 
is  described.  As  a  matter  of  fact  segmentation  in  this  species  is  carried  on 
after  an  entirely  novel  plan,  involving  the  formation  of  not  only  new  segments 
but  whole  chains  of  them  or,  indeed,  whole  strobilas  from  the  original  larval 
or  primary  strobila  as  it  is  here  called. 

The  original  larva  which  resembles  the  bothriocephalid  plerocercoid, 
excepting  for  the  peculiar  scolex,  gradually  elongates  with  growth,  imtil 
between  a  length  of  4  or  5mm.  the  first  traces  of  segmentation  appear  in  the 
hinder  ends  of  cleared  specimens  as  feeble  aggregations  of  nuclei  forming  faint 
dark  lines  at  regular  intervals.  In  one  specimen  4.8mm.  in  length  five  intervals 
were  made  out,  the  second  last  of  which  was  0.37mm.  in  length  by  0.20mm. 
in  diameter,  while  the  last  one  was  shghtly  larger  and  rounded  posteriorly. 
These  primary  segments  elongate  with  the  growth  of  the  strobila,  and  the 
constrictions  between  them  gradually  deepen  as  their  anterior  and  posterior 
ends  enlarge  shghtly,  the  former  relatively  faster  than  the  latter.  When  a 
total  length  of  strobila  of  about  10mm.  is  reached,  the  hindermost  segment. 


48  ILUNOIS  BIOLOGICAL  MOXOGILiPHS  [336 

itself  now  about  1.5mm.  in  length,  begins  to  show  faint  transverse  lines  in  its 
anterior  end,  decreasing  in  intensity  from  ahead  backwards.  These  are  the 
earliest  traces  of  the  divisions  of  the  primary  segments  into  the  secondary  seg- 
ments which  will  become  the  definitive  joints  of  the  anterior  ends  of  the  adult 
strobilas.  In  other  words  the  original  primary  larva,  plerocercoid  or  strobila, 
divides  up  into  secondary  strobilas  which  eventually  separate  from  each  other 
and  grow  into  the  adult  chains  as  described  above  for  the  species.  But  long 
before  separation  takes  place  the  entire  development  of  the  anterior  segments 
with  their  characteristic  posterior  auricular  appendages  and  the  formation  in 
particular  of  the  first  segment  can  be  followed  in  these  primary  strobilas  (Fig. 
44).  Whereas  originally  (Cooper  1914a :82,  Figs.  5  and  6,  PI.  V)  attention 
was  drawn  to  young  scolices  with  only  5  to  8  segments,  it  was  found  in  connec- 
tion with  the  present  study  that  the  latter  number,  about  8  in  external  view 
or  16  or  17  in  cleared  specimens,  is  in  reality  that  developed  by  the  secondary 
strobilas  before  detachment  from  the  original  chain.  The  smaller  strobilas 
are  now  looked  upon  as  havang  been  prematurely  and  accidentally  separated 
from  the  posterior  end  of  the  primar}-  strobila.  The  attachment  soon  be- 
comes very  slight,  owing  to  the  rapid  deepening  of  the  constriction  ahead 
of  the  first  segment,  so  that  some  time  before  the  auricular  appendages  of  the  lat- 
ter are  fully  delimited  posteriorly  very  Uttle  manipulation  of  even  alcohohc 
specimens,  let  alone  cleared  ones,  suffices  to  break  up  the  chain.  However, 
there  was  found  intact  in  the  material  at  hand  one  primary  strobila  88mm.  in 
length,  showing  twenty  secondary  strobilas,  including  the  imdifferentiated 
anterior  segments  from  which  they  are  developed.  Furthermore,  the  last 
two  of  these,  10.4  and  11.5mm.  in  length,  showed  in  their  posterior  unseg- 
mented  portions  the  earUest  traces  of  the  rudiments  of  the  reproductive  or- 
gans. As  has  been  already  intimated  the  anterior  segments  form  within  the 
secondary  or  definitive  strobilas  by  a  gradual  demarcation  from  head  back- 
wards, fijst  internally  in  the  parenchyma — actually  as  transverse  layers  of 
nuclei  (Fig.  44)  which  will  eventually  form  the  posterior  axiricular  appendages 
— and  then  externally  as  shown  in  the  figure. 

A  continued  search  for  evidence  in  connection  with  the  question  of  whether 
or  not  there  is  in  the  secondary  strobila  a  definite  number  of  segments  (external 
and  genital  combined)  brought  out  further  interesting  facts.  The  number 
was  counted  in  several  young  strobilas,  evidently  not  long  separated  from 
the  primary  strobila,  with  the  following  results  in  the  case  of  four  typical  speci- 
mens: (1)  Length,  19mm.,  number  of  segments,  45;  (2)  27mm.,  29  or  30; 
(3)  26.5mm.,  30  (the  posterior  ones  here  ripe  as  in  the  next  specimen);  (4) 
41mm.,  32  segments.  It  would  seem  from  these  data  that  there  is  a  more  or 
less  definite  number  of  segments,  which  might  be  considered  to  be  about  30. 
But  in  No.  3  segments  9,  10  and  11  were  not  only  much  elongated  but  further 
subdivided  anteriorly;  while  in  No.  4  similar  conditions  were  present  in  seg- 
ments 10, 11  and  12,  excepting  that  in  the  case  of  the  eleventh  the  aggregations 
of  nuclei  indicating  the  subdivisions  were  in  the  posterior  end.  Similar  elonga- 
ted segments  in  still  other  strobilas  show  this  condition  in  their  middle  regions. 


337]  PSEUDOPHYLLIDEA  PROM  FISHES— COOPER  49 

Thus  there  is  a  tertiary  subdivision  of  the  secondary  segments,  which  must, 
however,  be  considered  as  by  no  means  as  regular  as  the  secondary  subdivision 
of  the  original  primary  segments.  These  facts  explain  the  aberrant  nature  of 
the  strobila  in  this  region,  noted  formerly  by  the  writer,  and  the  presence  in 
material  of  chains  showing  anteriorly  very  yoimg  segments  similar  to  those 
formed  in  the  oldest  attached  secondary  strobilas  but  posteriorly  much  older 
segments  with  well-developed  auricles  and  farther  back  the  typical  mature 
proglottides  of  the  ordinary  strobila.  Consequently  it  is  probable  that  there 
is  not  a  definite  number  of  segments  formed,  but  that  further,  irregular  and 
evidently  indefinite  subdivision,  resulting  in  the  formation  of  an  inconstant 
number,  takes  place  chiefly  in  the  middle  portion  of  the  anterior  segmented 
region  of  what  now  must  obviously  be  called  the  secondary  strobila. 

In  the  hght  of  this  method  of  segmentation  certain  facts  in  connection  with 
the  nervous  and  excretory  systems  that  were  previously  considered  to  be  very 
unique,  to  say  the  least,  will  now  be  expUcable.  In  primary  strobilas,  even 
those  that  are  youngest,  the  excretory  system  consists,  as  in  the  adult,  of  a 
larger  median  vessel  and  two  lateral  vessels  which  run  backward  and  unite 
in  the  posterior  end  to  form  a  plexus  from  which  very  many  small  vessels 
pass  to  the  exterior  by  prominent  foramina  secundaria  piercing  the  cuticula, 
much  as  described  by  Fraipont  (1881:11,  Fig.  7,  PL  II)  for  Bothriocephdus 
scorpii.  In  the  youngest  larva  I  have  been  able  to  find  only  the  median 
vessel,  which  becomes  greatly  reduced  in  diameter  about  twice  the  length 
of  the  bulbs  from  the  anterior  end  is  present  in  the  scolex.  It  forms  a  simple 
plexus  among  the  bulbs  anteriorly.  In  primary  strobilas,  however,  in  which 
segmentation  has  gotten  well  under  way,  all  three  vessels  are  quite  prominent. 
They  pass  close  to  each  other  as  well  as  to  the  chief  nerve  strands,  when  they 
traverse  the  constrictions  between  the  developing  secondary  strobilas,  where  the 
median  vessel  is  somewhat  enlarged.  As  they  near  the  anterior  end  of  the 
worm  they  give  off  numerous  branches  of  their  own  calibre,  and  when  they 
meet  the  large  ganglionic  mass  described  below,  diverge  as  four  vessels  (two 
on  each  side)  and  continue  lateral  to  the  bulbs  to  the  tip  of  the  scolex.  Here 
after  forming  an  open  plexus  among  the  anterior  ends  of  the  former,  they  unite 
in  a  single  median  frontal  loop.  As  the  constrictions  between  the  secondary 
strobilas  deepen  all  three  vessels  likewise  become  gradually  constricted  until 
eventually  they  are  cut  off,  and  the  adult  conditions  are  subsequently  developed 
by  the  simple  process  of  the  turning  in  of  both  severed  ends.  And  since  in 
these  yoimger  forms  the  median  vessel  is  considerably  enlarged  at  the  region 
of  constriction,  it  remains  thus  in  the  hinder  end  of  tlie  adult  strobila  as  weU 
as  in  the  first  segment — as  described  and  figured  elsewhere  by  the  writer 
(1914a :93,  Figs.  12,  37) — ^while  in  the  latter  it  is  joined  by  the  lateral  vessels 
to  form  the  characteristic  terminal  vesicle. 

The  nervous  system  of  the  primary  strobila  consists  of  two  chief  strands 
passing  thniout  the  segments,  a  quite  irregular  commissure  connecting  them 
anteriorly,  and  a  very  large  ganglionic  mass  situated  some  distance  posterior 
to  the  proboscis  bulbs.    The  chief  nerve  strands,  which  are  quite  indistinct 


so  ILUNOIS  BIOLOGICAL  MONOGRAPHS  [338 

at  different  levek  but  constantly  located  in  the  median  frontal  plane,  diverge 
as  they  meet  the  ganglionic  mass  in  passing  forward,  and  consequently  oppo- 
site the  bulbs  come  to  lie  close  to  the  subcuticula  laterally  (Fig.  65).  About 
0.2mm.  from  the  tip  of  the  scolex  they  are  united  by  a  very  irregular  but  com- 
paratively large  transverse  commissure,  from  which  large  trimks  pass  to  the 
neighboring  bulbs  both  forvs^ard  and  backward.  This  commissure  has  a  length 
or  longitudinal  diameter  of  about  0.10mm.,  while  its  maximum  depth  between 
the  lateral  pairs  of  proboscides  is  about  40/i.  It  gives  off  large  branches 
anteriad  to  the  lateral  walls  of  the  bulbs  and  caudad  to  the  central  walls.  In 
the  latter  case  a  large  branch  leaves  the  median  portion  of  the  comanissure, 
which  is  incidentally  freely  pierced  with  excretory  vessels  on  each  surface,  and 
shortly  divides  into  two,  each  supplying  the  central  walls  of  one  of  the  frontal 
pairs  of  bulbs  (Fig.  65).  The  anterior  branches  likewise  arise  in  a  common 
trunlc  on  each  side,  which  is  in  reality  the  continuation  of  the  lateral  ganglionic 
enlargements  of  the  commissure,  but  they  supply  the  outside  walls  of  the  lateral 
pairs  of  bulbs.  Imbedded  in  the  commissure  are  numerous  nuclei  which,  on 
account  of  their  larger  size  than  the  neighboring  parenchymatous  nuclei,  are 
probably  ganglionic  or  nervous  in  their  nature.  Just  behind  the  posterior  ends 
of  the  bulbs  and  extending  from  0.8  to  0.9mm.  farther  backwards  (Fig.  43)  there 
is  a  large  mass  of  large  nucleated  cells  which  in  transverse  sections  (Fig.  66) 
is  seen  to  occupy  the  whole  of  the  medulla  (and  about  the  whole  of  the  section) 
excepting  for  the  excretory  vessels.  These  cells  are  roughly  spherical  in  shape 
and  have  a  maximum  diameter  of  25/i,  their  nuclei  being  5/i.  On  account  of 
their  finely  granular  consistency  and  their  taking  the  counterstain  quite  like 
the  anterior  nervous  commissure  they  were  interpreted  as  being  ganglionic 
cells.  And  this  view  was  supported  on  closer  study  by  the  discovery  that  they 
are  not  only  united  laterally  with  the  chief  nerve  strands  (Fig.  66),  which  can 
scarcely  be  distinguished  from  them  at  various  levels,  but  with  each  other 
thru  a  complicated  plexus  of  fine  longitudinal  strands  which  pass  forward  to- 
wards the  bulbs  and  form  around  their  bases  an  almost  solid  mass  of  fibrils 
(Fig.  43).  From  this  mass  large  strands  from  10  to  15m  in  diameter  pass  into 
the  bases  of  the  bulbs,  one  for  each,  and  are  distributed  among  the  retractor 
muscles  of  the  proboscis  which  they  evidently  supply.  In  the  youngest 
primary  strobilas  but  not  in  the  older  ones,  this  mass  of  fibrils  at  the  bases  of 
the  bulbs  evidently  connects  forward  by  a  few  strands  with  the  commissure. 

Just  as  the  definitive  form  of  the  anterior  and  posterior  ends  of  the  excre- 
tory system  is  explained  by  the  separation  of  the  secondary  strobilas 
and  the  subsequent  growing  oyer  of  the  ends,  so  is  that  of  the  nerv'^ous 
system,  particularly  anteriorly.  As  was  noted  by  the  writer  (1914a)  in  connec- 
tion with  the  preparation  of  the  original  description  of  this  species  and  shown 
in  figure  11,  the  nerve-ring  is  drawn  out  anteriorly  into  a  point  which  is  directly 
opposite  a  small  conical  pit  in  the  tip  of  the  scolex.  This  fact,  as  well  as  the 
relatively  small  size  of  the  nerve-ring,  is  explained  by  the  contraction  of  the 
free  end  of  the  "  scolex  "  after  separation  and  the  growing  together  of  the  ends 
of  the  nerve  strands  to  form  the  ring.    The  close  association  cf  the  nerve-ring 


339]  PSEUDOPHYLLIDEA  FROM  FISHES— COOPER  51 

and  the  terminal  excretory  vesicle  is  also  comprehensible  in  the  light  of  this 
method  of  development,  for,  since  the  nerve  strands  are  situated  close  outside 
the  lateral  excretory  vessels  at  the  constrictions,  they  simply  turn  in  towards 
the  median  line  and  unite  immediately  ahead  of  the  junction  of  the  latter  with 
the  median  vessel. 

As  will  be  gathered  from  the  foregoing  description  there  is  a  most  remark- 
able resemblance  between  the  scolex  of  H.  globuliforme  and  that  of  the  Try- 
panorhyncha  not  only  in  the  structure  of  the  proboscides  but  also  in  the  pre- 
sence of  the  large  mass  of  ganglionic  cells  associated  with  them  posteriorly. 
Each  proboscis  consists  of  three  parts:  (1)  a  hollow  tentacle,  capable  of  eva- 
gination,  (2)  a  short  permanently  protruded  stump,  armed  with  thickly  set 
minute,  cuticular  spines,  and  (3)  a  comparatively  elongated  bulb.  Of  these 
parts  (1)  and  (3)  may  be  compared  respectively  with  the  proboscis  and  the 
bulb  of  Tetrarhynchus  or  Rhynchobothrius.  The  proboscis,  altho  not  pro- 
vided with  any  kind  of  armature,  is  nevertheless  supplied  with  a  group  of  well 
developed  retractor  muscles  which  are  evidently  analogous  at  least  to  the  single 
retractor  muscle  of  the  Trypanorhyncha.  The  bulb  is  not  only  provided  with 
a  musculature  arranged  so  as  to  diminish  on  contraction  the  volume  of  the 
organ,  but  is  also  lined  with  an  epithelium-like  layer  comparable  to  that  of  the 
members  of  the  latter  group.  But  since  the  bulb  extends  to  the  point  of  exit 
of  the  proboscis,  there  is  no  part  corresponding  strictly  to  the  proboscis -sheath 
of  Tetrarh)mchus  altho  the  stump  would  at  first  sight  seem  to  be  such.  Fur- 
thermore, the  cells  forming  the  large  mass  behind  the  bulbs  in  Haplobothrium 
which  are  here  interpreted  as  ganglionic  cells,  bear  not  a  little  resemblance  to 
those  described  by  Braun  (1896:1294)  after  Pintner  (1880),  Lang  (1881)  and 
Niemiec  (1888)  as  associated  with  the  bulbs  of  Tetrarhynchus  longicollis  (v. 
Ben.)  {  =  Dibothriorhynchus  ruficollis  Monticelli)  and  considered  by  some  to  be 
ganglionic  cells  and  by  others  myoblasts.  The  distribution  of  the  large  nerve 
trunks  arising  from  the  nerve  conamissure  is  also  somewhat  suggestive  of  con- 
ditions in  a  few  of  the  tetrarhynchids  (cf.  Braun  1896:1293). 

While  the  writer  is  not  prepared  to  go  further  into  this  comparison  he  would 
like  to  emphasize  the  significance  of  the  layers  composing  the  walls  of  the 
bulbs  in  H.  globuliforme  in  connection  with  the  possible  origin  of  these  most 
aberrant  structures.  In  discussing  the  homologies  of  the  proboscides  cf  the 
Trypanorhyncha  Benham  (1901)  said:  "It  appears  more  probable  (Pint- 
ner) that  each  proboscis  has  been  developed  by  the  deepening  and  modification 
of  an '  accessory  sucker'  of  some  Tetraphyllidean  as  its  relation  to  the  bothridia 
and  its  mode  of  development  closely  agrees  with  these  structures.  Func- 
tionally too  it  is  a  perfection  of  the  armature  plus  the  accessory  sucker  of 
three  forms  [Acanthocephala,  Nemertini,  and  Taenioidea];  whilst  there  is 
no  doubt  that  the  'phyllidea'  of  the  orders  are  identical. "  The  fact  that  here 
the  walls  of  the  bulb,  since  they  are  composed  of  an  outer  layer  of  longitudinal 
muscles,  a  middle  layer  of  circular  fibres  and  an  inner  cuticular  layer  are  not 
only  comparable  but  directly  continuous  with  the  cuticula  and  cuticular  mus- 
cles of  the  body  wall  and  in  the  reverse  order  would  seem  to  lend  support  to 


52  ILLINOIS  BIOLOGICAL  MONOGRAPHS  [340 

Pintner's  view.  Simple  invagination  of  the  external  layers  of  the  body  wall 
in  development  would  account  for  these  structures,  while  the  proboscis  with  its 
retractor  muscles  might  well  be  formed  by  the  modification  of  the  external  lay- 
ers of  an  "accessory  sucker." 


341]  PSEUDOPHYLLIDEA  FROM  FISHES— COOPER  53 


CYATHOCEPHALINAE  LiJhe  1899,  e.p. 

Scolex  unarmed,  not  longer  than  broad,  with  two  surficial  sucking  grooves, 
more  or  less  fused  with  one  another,  or  a  single  terminal  one  having  a  sucker- 
like structure.  External  segmentation  little  expressed  or  absent.  Genital 
organs  in  each  segment  simple.  Genital  openings  surficial,  median.  Vagina 
and  uterus  open  into  a  common  vestibule — in  young  proglottides  near  one 
another — lying  behind  the  male  opening  and  similar  to  the  genital  atrium  of 
other  cestodes,  which  may  be  surrounded  by  a  sphincter-like  musculature.  The 
genital  openings  of  the  different  segments  do  not  open  on  the  same  surface, 
but  alternate  irregularly  from  one  surface  to  the  other.  Uterus  a  coiled  canal 
without  uterus-sac.     Sexually  mature  in  the  intestines  of  fishes. 

Type  genus:  Cyathocephalus  Kessler. 

The  above  is  Liihe's  (1910:22)  diagnosis  modified  to  read  "may  be  sur- 
rounded, etc."  instead  of  "is  surrounded,  etc."  in  connection  with  the  genital 
sphincter,  since  there  is  no  such  structure  in  the  species  described  below. 

CYATHOCEPHALUS  Kessler  1868 


Taenia  (part.) 

Pallas 

1781 

Taenia  (part.) 

Batsch 

1786 

Echinorhynchus  (part.) 

Zeder 

1803 

Cephalocotyleum 

Diesing 

1850 

Cyathocephalus 

Kessler 

1868 

Cyathocephalus 

Grimm 

1871 

Monobothrium 

Grimm 

1871 

Acrobothrium 

Obson 

1872 

Cyathocephalus 

Zschokke 

1884 

Cyathocephalus 

Loennberg 

1889 

Cyathocephalus 

Kraemer 

1892 

Cyathocephalus 

Olsson 

1893 

Cyathocephalus 

Llihe 

1889 

Cyathocephalus 

Braun 

1900 

Cyathocephalus 

Liihe 

1900 

Cyathocephalus 

Luhe 

1910 

Scolex  a  single,  undivided,  terminal,  sucking  organ,  which  in  its  form  and 
structure  no  longer  shows  an  origin  from  two  fused  surficial  bothria.  External 
segmentation  only  slightly  indicated.  Sphincter  surrounding  the  female 
genital  cloaca  apparently  little  developed.    Occurrence:  In  Teleosts. 

Type  Species:  C  tnincatus  (Pallas,  1781). 

CYATHOCEPHALUS  AMERICANUS  Cooper  1917 
[Figs.  11,  82,  93,  99,  104] 
?  1898  Cyathocephalus  truncatus  Linton  1898:428 

1917  Cyathocephalus  americanus  Cooper  1917  :  35 

Specific  diagnosis:  With  the  characters  of  the  genus.  Small  cestodes,  up 
to  a  length  of  at  least  11mm.  with  a  maximum  breadth  of  1.2mm.    Scolex 


54 


ILLINOIS  BIOLOGICAL  MONOGRAPHS 


342] 


funnel-shaped,  0.3  to  0.6mm.  long  and  0.5  to  0.9  broad,  with  revolute  edges. 
Neck  1.0  to  1.8mm.  in  length.  Segments  twice  as  broad  as  long,  terminal  one 
rounded. 

Cuticula  5  to  6/i  in  thickness,  with  neither  hooks  nor  spines;  subcuticula 
25  to  50/x. 

Ten  to  twenty  sets  of  genitalia,  beginning  1.5  to  2.0mm.  from  the  anterior 
end.  Strong  tendency  for  the  reproductive  apertures  to  lie  all  on  one  surface 
of  the  strobila.  Vagina  opens  behind  the  uterus.  Neither  papillae  nor 
sphincters  around  the  genital  openings. 

Testes  in  two  lateral  fields  in  the  medulla  of  the  anterior  portion  of  the 
proglottis,  60  to  IQix  in  diameter.  Coiled  vas  deferens  anterodorsal  to  cirrus- 
sac;  no  seminal  vesicle  before  entering  cirrus-sac  nor  connective  tissue  sack 
surrounding  the  whole  duct.  Protruded  cirrus  0.2mm.  in  length  by  0.12  in 
diameter  at  base.  Cirrus-sac  ovoid  in  shape  0.20  to  0.23mm.  in  length  by  0.17 
in  diameter;  no  retractors  connecting  it  with  the  dorsal  body- wall;  large  mass 
of  glandular  pigmented  cells  surrounding  it  dorsally  and  laterally. 

Vagina  12  to  15m  in  diameter;  no  sheath  near  its  opening;  receptaculum 
seminis  50  to  75/x.  Spermiduct  very  short  and  narrow,  25  and  8/i  respectively. 
Ovary  tubulolobular,  fan-shaped;  wings  extending  dorsally  and  laterally  around 
the  ventral  genital  ducts;  isthmus  prominent,  0.18  by  0.10mm.;  ova  in  same 
13  to  15/x  in  diameter.  Oocapt  25/x  in  diameter.  Vitelline  follicles  continuous 
from  proglottis  to  proglottis,  forming  a  layer  90/i  thick  in  the  cortical  paren- 
Chjmtia,  20  to  35  in  transections.  Shell-gland  dorsal.  Uterine  rosette  not 
surrounded  by  a  muscular  sac,  but  the  organ  is  enveloped  proximally  by 
nimierous  glandular  cells. 

Eggs,  40  by  30/1. 

Habitat:  In  stomach,  pyloric  ceca  and  intestine  of  the  host. 


HOST 

LOCALITY 

COLLECTOR 

AUTHORITY 

{?)Coregonus  clupeiformis 

Outer  Id.,  L. 
Superior 

J.  W.  Milner 

Linton           1898  :429 

»                » 

Off  Giant's  Tomb 

Cooper 

Cooper  (the  present 

Id.,  Georgian 

paper) 

Bay,  L.  Huron 

>»                » 

Charlevoix, 
Mich. 

tt 

» 

Type  specimen:  No.  165A,  in  the  writer's  collection. 

Co-type:  No.  165B,  in  the  collection  of  the  University  of  Illinois. 

Type  locality:  Georgian  Bay,  Lake  Huron,  off  Giant's  Tomb  Island. 


Altho  the  species  described  here  is  closely  related  to  C.  truncatus  of  Europe, 
it  presents  so  many  differences  from  that  species,  even  barring  some  probable 
errors  by  Kraemer  (1892),  that  it  is  considered  to  be  new.  Probably  the  same 
form  was  reported  by  Linton  (1898:428). 


343] 


PSEUDOPHYLLIDEA  FROM  FISHES— COOPER 


55 


As  shown  in  the  appended  table  where  the  largest  specimens  at  hand  are 
dealt  with,  this  species  is  considerably  smaller  than  the  European  species 
which  ranges  from  6  to  40mm.  in  length  by  1 .5  to  4  in  width.  Linton  gave  these 
measurements  as  7  and  1.2mm. 

The  general  shape  of  the  body,  however,  is  the  same,  as  are  the  proportions 
of  the  scolex  and  proglottides.  The  border  of  the  infundibuliform  scolex 
(Fig.  11)  is  thickened  and  almost  constantly  rolled  backward  slightly  as  in  the 
figures  given  by  Zschokke  (1884a,  Fig.  9)  and  Kraemer  (1892,  Fig.  5).  The 
funnel  is  about  0.22mm.  in  depth,  and  is  usually  filled  with  a  plug  of  mucous 
membrane  from  the  host's  alimentary  tract.  The  posterior  limits  of  the 
scolex  are  difficult  to  define  since  the  organ  gradually  narrows  down  and  then  as 
gradually  enlarges  again  to  form  the  neck.  The  latter  is  considered  to  include 
that  portion  of  the  anterior  end  of  the  worm  between  the  narrowest  region 
behind  the  scolex  and  the  first  vitelline  follicles  which  are  situated  some  dis- 
tance ahead  of  the  first  cirrus-sac.  The  maximum  breadth  of  the  strobila  is 
at  the  posterior  end  of  either  the  first  third  or  one-half.  The  segments  are  as 
described  by  various  writers  for  C.  iruncatus  about  twice  as  broad  as  long,  the 
last  one,  however,  being  rounded  posteriorly  and  provided  with  a  notch  in  the 
middle  which  accommodates  the  exit  of  the  excretory  vesicle.  They  are, 
furthermore,  closely  united,  as  pointed  out  by  Linton  (1898:429)  when  he  said 
"The  bodies  of  these  specimens  appear  to  be  unsegmented,  or,  at  least, 
with  only  very  faint  indication  of  division  into  segments."  As  a  matter  of 
fact  numerous  transverse  wrinkles  present  in  most  specimens  make  it  almost 
impossible  without  the  external  evidences  of  the  inner  genitalia  to  distinguish 
the  limits  of  the  proglottides.  And  in  this  respect  they  agree  with  C.  truncatus, 
since  Zschokke  (1884:38)  said  concerning  the  segments:  "lis  sont  solidement 
fixes  les  uns  aux  autres,  leurs  limites  sont  difficilement  visibles. "  The  follow- 
ing table  gives  the  measurements  of  four  of  the  largest  specimens  studied: 


Length 

10mm. 

9mm. 

llmra. 

7.5mm. 

Maximum  breadth 

1.01 

0.92 

1.11 

1.05 

Length  of  neck 

1.4S 

1.00 

1.48 

1.8 

Breadth  scolex,  tip 

0.55 

0.53 

0.74 

0.64 

"             "  ,  base 

0.37 

0.42 

0.55 

0  30 

Length  of  scolex 

0.42 

0.33 

0.61 

0.50 

Number  of  sets  of  genitalia 

13 

12 

13 

10 

First  cirrus  from  ant.  end 

1.85 

1.66 

2.25 

2.01 

Remarks 

Toto 

Toto 

Toto 

Sectioned 

The  cuticula  is  5/j,  in  thickness  over  the  scolex  as  well  as  on  the  segments, 
and  is  divided  into  two  layers,  the  outer  of  which  is  about  one-half  as  thick  as 
the  inner  and  more  or  less  irregular  in  structure.  However,  no  such  chitinous 
hooks  as  described  by  Kraemer  (1892 :10)  for  the  cuticula  of  the  lateral  borders 
were  seen,  but  the  whole  tissue  is  freely  pierced  with  numerous  foramina 
secundaria  of  the  excretory  .system,  which  in  C.  truncatus  Kraemer  considered 


56  ILLINOIS  BIOLOGICAL  MONOGRAPHS  [344 

to  be  the  points  of  entrance  of  nutriment.  The  thickness  of  the  cuticula, 
according  to  the  same  author,  is  19/i,  an  outer  irregular  layer  being  Sjix  and 
showing  a  sort  of  ecdysis  ("Hautungsprocess").  This,  however,  may  be 
simply  the  separation  of  the  outer  layer  of  the  cuticula  from  the  inner  which 
often  appears  in  sections,  since  he  said,  "Diese  Auffassung  wird  dadurch 
erhartet,  dass  sich  an  einigen  Stellen  dieser  Belag  nicht  findet,  dafiir  eine  junge 
homogene  Cuticula, " — the  latter  being  then  the  inner  homogeneous  layer.  At 
any  rate,  it  is  quite  evident  that  the  cuticula  of  C.  truncatus  is  a  much  thicker 
tissue  than  that  of  the  form  described  here — and  no  one  else  than  Kraemer 
seems  to  have  described  it. 

The  subcuticula  is  comparable  to  that  of  C.  truncatus  in  that  it  varies  in 
thickness  from  25  to  40ju.  It  is  composed  of  considerably  elongated  columnar 
cells  whose  nuclei,  5/x  in  diameter,  are  as  thick  as  the  cells  themselves.  Scat- 
tered spaces  in  the  loose  parenchyma,  which  evidently  accommodated  cal- 
careous bodies  before  they  were  dissolved  in  the  fixing  fluid,  were  found  to  be 
ellipsoidal  to  almost  spherical  in  shape  and  to  vary  from  13  to  25ju  in  length 
by  7  to  18  in  width.  Linton  stated  that  the  calcareous  bodies  of  C.  truncatus 
are  10  to  20/x  long,  Zschokke  that  they  are  8  to  lO/x  and  Kraemer  that  their 
size  is  30  by  18/i. 

In  general  the  musculature  is  as  described  by  Kraemer,  but  all  the  groups 
are  comparatively  weakly  developed  (Fig.  82).  The  longitudinal  layer,  for 
instance,  is  only  20;u  in  thickness  in  the  median  line  posteriorly  and  about  60^ 
in  the  neck  region  (76^i  in  C.  tnmcatus)  where  the  dorsoventral  and  transverse 
fibres  are  also  much  stronger  than  elsewhere.  In  the  anterior  part  of  the  neck, 
particularly  immediately  behind  the  scolex,  the  fibres  of  the  two  latter  series 
are  much  stronger,  altho  less  numerous  than  farther  back.  Just  ahead  of  the 
posterior  end  of  the  funnel  they  become  arranged  in  an  arcuate  manner  longi- 
tudinally as  well  as  transversely.  Then  from  there  on  to  the  tip  of  the  scolex 
they  gradually  become  more  numerous  as  they  concentrate  around  the  funnel 
of  the  organ,  of  which  they  obviously  act  as  constrictors.  Antagonizing  these 
are  numerous  weaker  radial  fibres,  arranged  as  in  C.  catenatus  Riggenbach 
{  =  Diplocotyle  rudolphii  Mont.)  where  they  were  considered  by  Riggenbach 
(1898:639)  to  be  derived  from  the  longitudinal  muscles  with  which  they  are 
continuous  at  the  base  of  the  scolex.  Altho  they  mingle  freely  among  the 
latter,  they  are  still  quite  separate  from  them.  Thus  the  writer  is  inclined  to 
the  same  view  regarding  their  homologies  in  C.  americanus,  since  it  seems  clear 
that  the  dorsoventral  and  transverse  fibres,  which  might  otherv.dse  be  con- 
sidered to  give  rise  to  them,  become  modified  to  form  the  circular  muscles  of  the 
scolex.  As  a  matter  of  fact  only  a  very  few  of  the  longitudinal  muscles  of  the 
neck  pass  for  a  short  distance  beyond  the  bottom  of  the  funnel;  most  of  them  are 
inserted  in  the  latter,  thus  functioning  with  the  radial  fibres  in  enlarging  the 
organ  of  adhesion.  According  to  Riggenbach  these  radial  muscles  are  ap- 
parently absent  from  C.  truncatus.  They  were  not  described  by  Kraemer;  but 
the  enlargement  of  the  funnel  was  considered  to  be  accomplished  by  the  con- 
traction of  the  dorsoventral  fibres  (cf.  his  Fig.  1).    The  outermost  layer  of 


345]  PSEUDOPHYLLIDEA  FROM  FISHES— COOPER  57 

circular  and  longitudinal  muscles  in  the  scolex,  which  are  merely  extensions 
of  the  cuticular  muscles  of  the  neck  region,  are  not  nearly  so  strongly  developed 
as  in  C.  truncatus.  There  is,  however,  in  the  neck  region,  particularly  in  its 
anterior  portion,  a  series  of  outer  longitudinal  muscles  which,  altho  situated 
in  transections  among  the  outer  clear  ends  of  the  subcuticular  cells  and  very 
close  to  the  longitudinal  cuticular  fibres,  are  nevertheless  quite  distinct  from 
the  latter.  At  the  base  of  the  scolex  they  pass  inwardly  between  the  cells  of 
the  subcuticula  and  continue  farther  towards  the  anterior  border  of  the  funnel 
than  do  the  inner  or  main  longitudinal  fibres.  Posteriorly  they  diminish  con- 
siderably in  number  but  may  readily  be  seen  in  the  mature  proglottides. 

The  nervous  system  is  arranged  in  general  as  in  C.  truncatus;  but  the 
longitudinal  trunks  are  only  26ju  thick  by  13  wide  (0.345mm.  according  to 
Kraemer).  In  the  neck  they  are  scarcely  enlarged  to  form  ganglia,  such  as 
shown  in  Kraemer's  Fig.  5,  but  each  is  divided  into  two  distinct  dorsoventral 
halves  which  gradually  diverge  as  they  pass  on  into  the  scolex  to  form  four  large 
nerves.  There  is  no  single  transverse  commissure  connecting  the  main  trunks 
behind  the  funnel  of  the  scolex  but  instead  a  number  of  fine  cross-connections 
which  are  often  difficult  to  make  out  satisfactorily. 

As  regards  the  excretory  system  there  is  an  inconstant  number  of  longi- 
tudinal vessels  in  transection,  evidently  more  than  the  six  of  C.  truncatus,  which 
do  not  occupy  definite  positions  but  anastomose  freely  with  each  other  especial- 
ly in  the  lateral  portions  of  the  medulla.  In  the  scolex  these  vessels  are  smaller 
and  the  anastomoses  are  much  more  numerous,  while  posteriorly  at  least  two 
pass  into  a  quite  irregularly  shaped  terminal  vesicle,  which,  however,  in  the 
Ught  of  Wolf's  (1906)  findings  cannot  be  considered  to  be  a  true  terminal 
excretory  vesicle.  As  above  stated,  foramina  secundaria  are  quite  numerous 
in  the  cuticula. 

The  reproductive  organs  appear  quite  close  behind  the  neck,  the  vitelline 
folHcles  being  situated  from  1.3  to  2.3mm.  from  the  anterior  border  of  the 
scolex,  and  the  first  cimis-sacs  from  1.6  to  2.2mm.  From  10  to  20  sets  of 
genitaUa  were  observed  for  this  species.  These  follow  each  other  closely  and 
are  not  separated  by  any  septa  or  other  boundaries,  the  vitelline  foUicles  being, 
in  fact,  strictly  continuous  from  proglottis  to  proglottis.  The  openings  of  the 
cirrus-sacs  vary  from  0.45  to  0.75mm.  apart,  but  as  pointed  out  by  Kraemer, 
these  measurements  are  of  Httle  diagnostic  value  on  account  of  the  different 
states  of  contraction.  As  in  C.  truncatus  the  reproductive  openings  are  all  on 
one  surface  of  the  proglottis  but  alternate  as  a  unit  irregularly  from  one  surface 
to  the  other.  There  is,  however,  a  strong  tendency  for  them  to  lie  all  on  the  one 
face  of  the  strobila.  This  alternation  also  involves  the  ovary,  the  isthmus  of 
which  is  arbitrarily  considered  in  the  cestode  to  be  ventral.  It  usually  lies 
on  the  same  surface  as  the  reproductive  openings,  so  that  when  the  latter  passes 
to  the  opposite  surface  it  moves  accordingly.  This  alternation  of  the  openings 
has,  of  course,  been  known  ever  since  Pallas  described  Taenia  truncata  in  1781, 
but,  so  far  as  the  writer  is  aware,  no  one  has  dealt  --Adth  the  relations  between 
the  openings  and  the  ovary  noted  here.     Concerning  this  matter  Kraemer 


58  ILLINOIS  BIOLOGICAL  MONOGRAPHS  [346 

said  only:  "Das  Verhalten,  dass  die  Geschlechtsorgane  altemirend  dorsal  und 
ventral  nach  aussen  miinden,  erinnert  in  gewisser  Beziehung,  an  die  altemier- 
ende  marginalen  Greschlechtsoffnungen  verschiedener  Fisch-  und  Vogeltaenien 
und  wurde  bereits  von  den  ersten  Beobacht'er,  Pallas  und  Batsch  erkannt,  d.h., 
sie  hatten  auf  beiden  Flachen  die  fortlaufende  Reihe  der  'Punkte'  wahrge- 
nommen,  ohne  sie  indessen  als  Ausmiindungen  der  Sexualorgane  zu  deuten. 
Die  neueren  Beobachter  haben  sammtlich  dieses  oben  beschriebene  Verhalten 
iibersehen,  und  geben  die  Geschlechtsoffnungen  als  ventral  gelegen  an. "  But 
whatever  is  the  stimulus  which,  during  the  very  eariy  stages  of  development 
of  the  sets  of  genitalia  from  their  rudiments,  causes  the  reversal  of  the  whole 
proglottis,  it  would  seem  to  be  such  at  times  as  to  fail  to  bring  about  the  turning 
over  of  all  parts  of  the  rudiment.  As  shown  in  figure  104,  which  is  a  diagram  of 
a  sagittal  series  of  seven  proglottides  including  the  terminal  one,  the  cirrus 
and  female  genital  cloaca  of  number  three  from  the  top  have  gone  to  the  oppo- 
site surface  while  the  ovarian  isthmus,  represented  by  the  solid  black  disc  in 
each  segment,  has  remained  on  the  same  surface  as  those  in  segments  1 ,  2  and 
4  in  the  immediate  neighborhood.  Here  the  stimulus  which  brought  about 
the  unisurficiality  of  the  latter  may  have  influenced  the  ovarian  portion  of  the 
common  rudiment  of  number  three  and  caused  it  to  lag  behind,  while  the  more 
peripheral  rudiments  of  the  cirrus,  vagina  and  distal  portions  of  the  uterus  were 
freer  to  move.  This  arrangement  of  the  parts  in  the  aberrant  segment  in 
question  naturally  causes  considerable  departures  in  the  courses  of  the  repro- 
ductive ducts  from  the  normal. 

The  genital  openings  vary  from  75  to  llS/i  apart,  but  again  as  pointed  out 
by  Kraemer  these  data  are  of  very  little  specific  value.  The  vagina  and 
uterus  open  into  a  common  genital  sinus  or  cloaca,  but  unlike  conditions  in  the 
European  species  the  vagina  opens  constantly  behind  the  uterus  and  slightly 
to  one  side  and  not  ahead  of  it.  Furthermore,  neither  papillae  nor  sphincter 
muscles  are  present  around  either  or  both  genital  openings  in  this  species.  The 
female  genital  cloaca,  usually  situated  at  the  bottom  of  a  depression  and  often 
on  a  low  papilla,  ranges  from  30  to  60;ti  in  depth.  In  frontal  sections  it  is  seen 
to  be  in  the  form  of  a  transverse  slit  about  60m  in  length,  into  the  ends  of  which 
the  vagina  and  uterus  empty;  that  is,  the  vagina  opens  diagonally  behind  the 
uterus  and  usually  to  the  right  of  it.  It  is  lined  by  a  direct  continuation  of  the 
cuticula  from  the  surface  of  the  segment.  The  general  habit  of  the  reproduc- 
tive organs  is  shown  in  figure  93,  which  is  from  a  frontal  section  of  a  mature 
proglottis. 

The  majority  of  the  testes  are  situated  in  the  medullary  parenchyma  in  two 
fields  lateral  to  the  cirrus-sac,  or  more  strictly  speaking,  in  the  lateral  portions 
of  the  region  between  the  cirrus-sac  and  the  ovary  of  the  proglottis  ahead, 
since  they  usually  extend  forward  to  the  latter  and  backward  to  the  anterior 
ends  of  the  wings  of  the  ovary  of  the  segment  to  which  they  belong.  While 
their  shape  is  usaully  spherical  or  somewhat  flattened  anteroposteriorly  accord- 
ing to  the  condition  of  contraction  of  the  segment,  their  maximum  diameter 
is  about  70/i.    The  coils  of  the  vas  deferens,  altogether  about  0.30mm.  in  dia- 


347]  PSEUDOPHYLLIDEA  FROM  FISHES—COOPER  59 

meter,  are  accommodated  in  the  somewhat  confined  space  dorsal  and  anterior 
to  the  cirrus-sac,  extending  to  the  ovary  ahead  (Fig.  93).  Whereas  Kraemer 
gave  the  diameter  of  the  duct  as  0.133mm.  or  about  eight  times  as  large  as  just 
before  it  enters  the  cirrus-sac,  it  is  only  45/i  at  the  most  in  this  species.  Fur- 
thermore, it  is  not  enlarged  to  form  a  seminal  vesicle  close  to  the  cirrus-sac, 
as  shown  in  Kraemer's  figiu-es  6  and  13,  but  gradually  diminishes  in  size  until 
as  it  pierces  the  wall  of  the  latter  its  diameter  is  only  lOju.  Nor  is  the  whole 
vas  deferens  enclosed  in  a  connective  tissue  sac,  such  as  described  by  Kraemer. 
Within  the  pouch  it  enlarges  considerably  to  form  a  thin-walled  inner  seminal 
vesicle,  situated  for  the  most  part  near  the  proximal  end  of  the  former  but  often 
lying  alongside  the  cirrus  proper.  This  portion  of  the  duct  may  attain  a 
diameter  of  30^  even  when  empty.  Then  follows  the  cirrus  proper  which  is 
sharply  separated  from  the  seminal  vesicle;  as  a  matter  of  fact  it  actually  pro- 
trudes backward  into  the  latter  with  a  diameter  of  lO/z  and  for  a  distance  of 
from  15  to  25/i.  The  extruded  cirrus  has  a  maximum  length  of  200)u,  diameter 
at  the  base  of  120/Lt,  and  at  the  tip  of  about  40;ti.  The  thick  cuticula  covering 
the  organ  is  decidedly  roughened  or  irregularly  "cleft,"  especially  towards  the 
tip,  but  not  provided  with  spines  of  any  kind.  Incidentally,  the  protrusion  of 
the  cirrus  on  account  of  its  size,  results  in  the  eversion  of  almost  the  whole  of 
the  contents  of  the  sac.  The  length  of  the  cirrus  within  the  sac  is  at  least  185^, 
— it  is  usually  bent  once  in  its  proximal  portion — while  its  diameter  varies 
considerably.  The  layer  of  parenchymatous  and  myoblastic  nuclei  surround- 
ing the  cirrus  within  the  sac  is  about  lO/x  in  thickness  as  compared  with  5/i  in 
C  truncatus.  In  sections  of  the  extended  cirrus  most  of  these  nuclei  appear  in 
the  tip  of  the  organ  surrounding  a  good  deal  of  the  cuticula  which  still  remains 
invaginated;  but  they  are  in  all  probability  myoblastic  as  are  others  farther 
back  along  the  course  of  the  retractor  fibres.  In  frontal  sections  the  cirrus-sac 
is  circular  in  outline  (Fig.  93),  its  maximum  diameter  being  175ju,  while  in 
transverse  and  longitudinal  sections  it  is  oval  in  shape  and  the  diameter  (length 
of  the  organ)  ranges  from  200  to  230/x.  The  smaller  end  is  directed  ventrally. 
Its  wall  is  comparatively  thin,  ill  defined,  and  composed  of  a  somewhat  loose 
network  of  muscular  fibres  running  irregularly  obUquely  in  all  directions,  so 
that  sections  cut  in  any  plane  show  them  almost  circularly  arranged.  Owing 
to  this  fact  and  to  the  further  fact  that  its  innermost  fibres  are  not  easily  dif- 
ferentiated from  the  retractors  of  the  cirrus  proper  which  bulk  largely  in  the 
contents  of  the  sac,  the  wall  is  fairly  difficult  to  locate  with  emission  of  the  cir- 
;us.  The  sac  is  furthermore  not  provided  with  any  retractors  connecting  it 
with  the  dorsal  body- wall  as  described  by  Kraemer  for  C  trmtcaius.  Forming 
a  sort  of  gland  closely  applied  to  that  part  of  the  cu-rus-sac  within  the  medulla 
there  is  to  be  seen,  even  in  toto  preparations,  a  comparatively  large  mass  of 
large  darkly  pigmented  polygonal  cells  (Fig.  93).  In  frontal  sections  they  He 
on  each  side  of  the  sac  but  do  not  extend  much  beyond  its  anterior  and  poster- 
ior edges,  the  whole  structure  being  thus  shaped  somewhat  like  a  saddle.  Each 
cell  is  elongate  in  shape  provided  with  a  well-defined  wall,  prominent  tho  not 
especially  large  nucleus,  and  very  granular  and  highly  pigmented  cytoplasm.. 


60  ILLINOIS  BIOLOGICAL  MONOGRAPHS  [348 

the  color  of  the  pigment  bemg  dark  brovm.  Altho  they  are  very  closely  ar- 
ranged around  the  wall  of  the  cirrus-pouch  and  most  of  them  are  quite  pointed 
towards  the  same,  their  fimction  is  pretty  much  a  matter  of  conjecture;  unless 
parhaps  they  are  the  much  modified  myoblasts  of  the  muscles  of  the  walls 
of  the  pouch.  This  is  suggested  by  the  intimate  relations  of  the  inner  at- 
tenuated ends  of  some  of  them  with  the  latter.  No  such  ceUs  have  been  de- 
scribed for  the  European  species,  so  far  as  the  writer  is  aware.  It  would  seem, 
however,  that  certain  "radiar  gesteUten,  kolbenformigen  Driisen,"  merely 
mentioned  and  figm-ed  by  Linstow  (1904:308,  Fig.  26)  as  surroimding  the 
cirrus-sac  of  Botkrimmius  pachycephdus  Linstov,*,  are  similar  to  these  pecviliar 
ceUs.  But  in  the  latter  species  they  are  evidently  much  less  extensive  than  in 
C.  americanus.  Similar  glandular  cells  were  also  described  by  Schneida:  (1902: 
76)  for  Bothrimonus  nylandicus  Schneider. 

From  its  opening  which  has  been  dealt  with  above  the  vagina  proceeds 
dorsally  almost  at  right  angles  to  the  surface  of  the  proglottis,  and  then  within 
the  mediiQa  tiims  backward  with  a  few  coils  to  expand  into  a  comparatively 
oiormous  receptaculimi  seminis  which,  on  account  of  its  size,  can  scarcely  be 
distinguished  from  one  of  the  coils  of  the  uterus.  At  the  turn  in  its  course  the 
duct  has  a  diameter  of  about  15^  and  is  lined  vdXh  a  continuation  of  the  cuticula 
of  the  female  genital  cloaca,  5/*  in  thickness,  and  surrounded  by  a  layer  of 
circular  muscles.  As  it  passes  above  the  ovarian  isthmus  its  cuticular  lining 
gradually  diminishes  in  thickness,  so  that  the  seminal  receptacle  is  provided 
with  a  very  thin  layer  only.  While  the  latter  may  have  a  diameter  of  75/i  slight- 
ly behind  the  isthmus  of  the  ovary,  it  narrows  down  very  abruptly  before 
joining  the  oviduct  to  a  very  small  spermiduct,  8/i  in  diameter  and  about  25/1 
in  length.  In  distinct  contrast  with  C.  truncatus  there  is  no  "connective  tissue 
and  muscular  sac "  surrounding  the  beginning  of  the  vagina,  as  described  by 
Kraemer,  but  only  the  usual  mass  of  nuclei,  most  of  which  are  subcuticvilar  in 
their  nature.  The  ovary  (Figs.  82,  93)  is  a  tubuJolobular  organ,  the  limbs  of 
which  radiate  from  a  ventral  isthmus  laterally  as  far  as  the  nerve  strands, 
anteriorly  as  far  as  the  cirrus-sac,  and  dorsally  thruout  the  whole  of  the  medvdla, 
thus  surrounding  the  central  connections  of  the  genital  ducts  and  the  coils  of 
the  uterus  (Fig.  93).  The  wings,  in  whose  irregularly  shap>ed  tubules  young 
ova  in  various  stages  of  development  are  to  be  seen,  connect  with  the  rounded 
isthmus  by  narrow  portions  quite  as  described  and  figiired  by  Kraemer,  altho 
he  evidently  erroneously  called  the  isthmus  the  "ootjrp."  The  latter 
in  this  species  has  a  width  of  0.18mm.  by  a  length  of  0.10  as  compared  with  the 
similar  measurements  of  0.19  and  0.07mm.  in  the  case  of  C.  truncatus.  Ova 
from  the  isthmus  measured  from  13  to  15ju  in  diameter,  their  nuclei  7  to  8/x  and 
their  nucleoH  4/i,  those  of  the  latter  species  being  9  to  12/i  according  to  Grimm 
(1871)  and  15/*  according  to  Kraemer  who  gave  the  diameter  of  their  nuclei 
as  9n.  The  oviduct  begins  with  a  rather  short  oocapt  (Fig.  99),  25/i  in  dia- 
meter, and  proceeds  for  only  a  comparatively  short  distance,  with  a  diameter 
of  from  15  to  20/i,  before  being  joined  by  the  spermiduct.  A  little  farther 
dorsally  it  is  met  by  the  vitelline  duct  which  comes  from  the  ventral  portion  of 


349]  PSEU DOPEY LUDEA  FROM  FISHES— COOPER  61 

the  medulla  just  ahead  of  the  isthmus  where  it  is  formed  by  the  union  of  a  ri^t 
and  left  duct  as  in  C.  truncaius.  Thruout  its  dorsoventral  course  the  vitelline 
duct  is  expanded  to  form  a  vitelline  reservoir  which  may  reach  a  diameter  of 
40^1.  Immediately  outside  of  the  longitudinal  muscles  the  vitelline  foUicles 
form  a  compact  layer  from  70  to  90;i  in  thickness  (152^1  in  C  truncalus),  con- 
tinuous from  proglottis  to  proglottis  and  broken  only  immediately  aroimd  the 
reproductive  openings.  They  range  in  diameter  from  30  to  85/i,  while  their 
nimiber  in  transvCTse  sections  varies  from  20  to  35, 45  being  given  by  Kraemer. 
From  its  point  of  origin  to  a  short  distance  beyond  the  entrance  of  the  vitelline 
duct,  the  oviduct  is  lined  with  epithelial  cells  showing  prominent  nuclei  but 
indistinct  boundaries,  the  whole  being  thus  of  the  nature  of  a  syncitium.  But 
soon  this  epithelimn  becomes  modified  in  that,  as  the  duct  continues  with  a 
few  coils  to  the  opposite  side  of  the  proglottis,  its  cytoplasmic  portion  gets  quite 
thin,  while  the  nuclei  remain  more  nearly  the  same  size  relatively  speaking. 
Then  as  it  further  enlarges  dorsally  the  oviduct  is  surrotmded  by  an  incon- 
spicuous shell-gland.  However,  no  shell-gland  such  as  described  by  Kraemer 
was  foimd  in  this  species.  Beyond  the  ootype  the  duct,  in  reality  the  beginning 
of  the  uterus,  is  enveloped  for  a  considerable  distance  by  numerous  unicellular 
glands  which  at  first  sight  appear  to  constitute  a  second  and  voliuninous  shell- 
gland.  This  mass  of  glandular  tissue  is  so  extensive  in  fact,  that  it  occupies  in 
frontal  sections  about  one-half  of  the  posterior  half  of  the  uterine  rosette  (Fig. 
93).  The  individual  cells,  of  which  it  is  composed,  are  comj>aratively  short, 
stout  and  well  defined,  their  nuclei  being  large  and  the  nucleoplasm  clear  like 
the  cytoplasm.  Most  of  the  coils  of  this  tubular  uterus,  which  m3.y  attain  a 
diameter  of  0.10mm.  or  more  when  filled  with  eggs  (0.038min.  in  C.  truncalus), 
are  situated  just  behind  the  cirrus-sac.  Before  reaching  the  opening,  the 
position  of  which  has  been  stated  above,  the  tube  narrows  down  quickfy. 
Thruout  its  com-se  it  is  lined  with  a  much  attenuated  epithehum,  the  nuclei  of 
which,  however,  stand  out  prominently  towards  the  limaen.  In  this  species 
there  is  no  muscular  sac  surroimding  the  uterus,  as  described  and  figured 
by  Kraemer. 

The  largest  eggs  in  the  uterus  not  in  a  collapsed  state  were  found  to  be 
ellipsoidal  in  shape  and  40  by  30/i  in  size.  Linton  gave  their  size  when  pie- 
ser\'ed  in  acetic  acid  as  50  by  32n;  while  the  measurements  for  C.  truncaius 
have  been  given  as  95  by  76/Lt  (Kraemer)  and  44  to  51  by  33  to  36/x  (Liihe,  1910), 
Since  most  of  the  eggs  seen  in  the  uteri  of  the  sections  made  were  quite  young, 
many  of  them  not  ha\'ing  gone  thru  the  first  cleavage  as  \"et,  the  writer  is  of 
the  opinion  that  the  size  of  the  egg  of  this  species  is  probably  about  the  same 
as  that  given  by  Liihe  for  C.  truncaius  in  Europe. 

Altho  evidently  no  one  has  as  yet  studied  the  early  stages  in  the  develop- 
ment of  C.  truncaius,  Wolf  (1906)  discovered  that  the  intermediate  host  is 
Gammarus  pulex  and  that  the  transfer  to  the  final  hosts  is  a  direct  one.  As  re- 
gards the  life  history  of  C.  americanus  the  writer  can  only  say  that  he  is  of  the 
opinion  that  Pontoporeia  hoyi  (Stimpson  Mss.)  may  later  be  foimd  to  be  the 
intermediate  host  at  least  in  Georgian  Bay,  Lake  Hiu^n,  where  it  constitutes 
practically  the  only  food  of  Coregonus  clupeiformis. 


62  ILUNOIS  BIOLOGICAL  MONOGRAPHS  [350 

In  the  above  description  it  has  been  shown  that  this  species  differs  from 
the  well-known  C.  truncatus  of  Europe  in  a  great  many  points,  but  in  none  so 
radically  as  the  following:  The  absence  of  chitinous  hooks  on  the  cuticiila 
of  the  lateral  borders;  the  presence  of  radial  muscles  in  the  walls  of  the  scolex, 
and  of  a  number  of  fine  nerve  commissures  connecting  the  chief  nerve  strands 
anteriorly  instead  of  a  single  one;  the  vagina  opening  behind  the  uterus  opening; 
the  absence  of  papillae  and  sphincter  muscles  siurounding  the  genital  openings; 
no  enlargement  of  the  vas  deferens  to  form  a  seminal  vesicle  just  before  enter- 
ing the  cirrus-pouch;  no  connective  tissue  sac  surrounding  the  whole  of  the 
coiled  wzs  deferens;  the  absence  of  dorsal  retractor  muscles  of  the  cirrus-sac, 
and  the  presence  of  the  pecuhar  glands  closely  surrotmding  the  pouch;  no 
"connective  tissue  and  muscular  sac"  surrounding  the  beginning  of  the  vagina; 
the  very  different  central  connections  of  the  genital  ducts  as  regards  the  ovarian 
isthmus  ("ootyp"  of  Kraemer);  and  lastly,  the  absence  of  any  such  "shell- 
gland  "  as  described  by  the  same  author.  Consequently  it  has  been  considered 
to  be  specifically  different  from  the  European  form  and  given  a  new  name. 

The  material  studied  consisted  of  three  lots,  Nos.  43,  165  and  382 A  of  the 
writer's  colllection  from  the  stomachs  and  intestines  of  several  specimens  of 
Coregonus  clupeijormis  (Mitchell)  from  Lakes  Huron  and  Michigan  as  listed 
above. 

BOTHRIMONUS  Duvemoy  1842,  char,  emend. 


Bothrimonus 

Duvemoy 

1842 

Bothrimonus 

Dujardin 

1845 

Bothrimonus 

Diesing 

1850 

Cephalocotylea 

Diesing 

1850 

Dis>'mph}'tobothrium 

Diesing 

1854 

Diplocotyle 

Krabbe 

1874 

Diplocotyle 

Monticelli 

1890 

Bothrimoaus 

Monticelli 

1892 

Diplocotyle 

Braun 

1900 

Bothrimonus 

Braim 

1900 

Diplocotyle 

Liihe 

1900 

Bothrimonus 

Liihe 

1900 

Bothrimonus 

Schneider 

1902 

Diplocotyle 

Linstow 

1903 

Bothrimonus 

Linstow 

1904 

Scolex  with  two  surficial  and  almost  spherical  bothria  whose  forwardly 
directed  apertujres  may  be  separate  or  more  or  less  completely  fused  to  form 
a  single  terminal  opening,  according  to  the  degree  of  contraction  of  the  ridge 
separating  the  two  internally,  the  latter  representing  the  tip  of  the  scolex 
in  other  bothriocephaUds.  External  segmentation  completely  absent.  Female 
genital  cloaca  with  more  or  less  well  developed  sphincter.  Vitelline  foUicles 
in  the  cortical  parenchjTna  in  two  lateral  fields. 

Occurence:  In  species  of  Acipenser  and  in  teleosts. 

Type  species:  Bothrimonus  sturionis  Duvemoy. 


351]  PSEUDOPHYLLIDEA  FROM  FISHES— COOPER  63 

As  pointed  out  by  Schneider  (1902a  :72)  the  two  genera  Bothrimonus  and 
Diplocotyle  were  separated  by  Liihe  (1900:10)  only  on  the  basis  of  the  differ- 
ences in  degree  of  fusion  of  the  apertures  of  the  bothria  at  the  tip  of  the  scolex. 
As  a  matter  of  fact  the  remainders  of  the  generic  diagnoses  are  identical. 
Schneider  stated  that  the  material  of  his  B.  nylandicus  showed  that  these 
differences  were  simply  due  to  differences  in  degree  of  contraction  and  relaxa- 
tion of  the  scolex  and  in  particular  of  its  termination  which  is  the  ridge  separat- 
ing the  two  openings  of  the  bothria  either  externally  or  internally.  With 
considerable  retraction  of  this  ridge  or  septum  the  two  openings  fuse  to  form 
one,  while  with  relaxation  of  the  same  and  contraction  of  the  bothrial  walls 
the  apertures  are  more  or  less  separate,  according  to  the  species  present. 
While  in  none  of  the  few  spechnens  of  the  species  described  below  were  the 
openings  fused,  various  stages  in  the  formation  of  a  single  terminal  and  almost 
circular  opening  from  the  two  otherwise  separate  openings  were  observed 
in  some  material  from  Microgadus  tomcod  which  was,  however,  too  young  to 
be  determined  with  certainty  specifically.  Consequently,  it  seems  just  with 
the  present  state  of  our  knowledge  of  these  forms  to  unite  the  two  genera, 
Bothrimonus  and  Diplocotyle,  and  to  retain  the  older  name  of  Duvernoy,  as 
done  by  Schneider  but  not  recognized  by  Linstow  (1903;  1904:308). 

BOTHRIMONUS  INTERMEDIUS  Cooper  1917 
[Figs.  6-8,  45,  81,  94] 
1917  Bothrimonus  intermedius  Cooper  1917  :  35 

Specific  diagnosis:  With  the  characters  of  the  genus.  Small  cestodes  up 
to  45mm.  in  length  and  1.6  in  breadth.  Scolex  almost  spherical,  0.60mm. 
long,  0.75  wide  and  1 .0  thick.  Bothria  hemispherical,  their  apertures  ordinarily 
not  fused  to  form  a  single  terminal  opening.  Strobila  uniform  in  width  from 
a  short  distance  behind  the  scolex  to  the  posterior  end;  0.6mm.  in  thickness; 
more  convex  ventrally  than  dorsally. 

Cuticula  5m  in  thickness.  Nerve  strands  15  to  20/i  in  diameter;  each 
divides  into  two  branches  sagittally  before  entering  the  scolex;  transverse  com- 
missure diffuse.  Four  main  excretory  trunks  in  ripe  proglottides,  six  farther 
forward  passing  into  the  scolex;  all  in  the  medullary  parenchyma. 

Reproductive  organs  1.5mm.  from  scolex;  up  to  66  in  number.  Weak 
sphincter  around  the  common  female  cloaca.  Vagina  opens  close  behind  the 
uterine  pore  which  is  not  quite  in  the  median  line. 

Testes  in  two  lateral  fields  and  two  layers  between  the  excretory  trunks, 
continuous  from  proglottis  to  proglottis;  spherical  in  shape,  80  to  100^  in 
diameter.  Coils  of  vas  deferens  anterodorsal  to  cirrus-sac,  the  duct  30^  in 
diameter.    Cirrus-sac  oval,  75  by  45ac  ;  everted  cirrus,  60  by  85/x. 

Vagina  lO/i  in  diameter;  receptaculum  seminis,  40  to  60^;  spermiduct,  10/*. 
Ovary  crescentic  in  shape,  wings  tubulolobular;  isthmus  almost  spherical, 
0.1mm.  in  diameter.  Oocapt  25^  in  diameter,  oviduct  15  to  20/i.  Common 
vitelline  duct  120  by  30^.  Vitelline  folUcles  spherical,  60/x  in  diameter;  in  the 
lateral  thirds  of  the  strobila,  continuous  at  the  margins  of  the  same  and  from 


64  ILLINOIS  BIOLOGICAL  MONOGRAPHS  [352 

proglottis  to  proglottis.  Shell-gland  obscure.  Uterus  surrounded  by  glandu- 
lar cells  proximally;  0.2 5mni.  in  maximum  diameter. 

Eggs,  36  by  24jLt  in  dimensions. 

Habitat:  In  the  intestine  of  Pseudopleuronectes  americanus  (VValbaum), 
the  winter  flounder,  from  Brandy  Cove,  St.  CroLx  River,  at  St.  Andrews,  New 
Brunswick. 

Type  specimen:  No.  206.1  in  the  writer's  collection. 

Co-type:  No.  206.2  from  the  same,  deposited  in  the  collection  of  the  Uni- 
versity of  Illinois. 

Since  1842,  when  Duvernoy  described  Bothrhnonus  sturionis,  the  type 
species  and  the  only  one  reported  for  America  up  to  date  from  a  specimen  of 
Acipenser  oxyrhynchus  Mitchill  {  =  A.  sturio  L.)  collected  by  M.  Lesueur  in 
1835,  the  following  species  have  been  found  in  Europe:  Diplocotyle  olrikii 
Krabbe  (1874),  D.  rudolphii  Monticelli  (1890:205),  B.fallax  Luhe  (1900b:257), 
B.  nylandicus  Schneider  (1902a :72),  D.  cohaerens  Linstow  (1903:291)  and  B. 
pachycephalus  Linstow  (1904:307).  As  pointed  out  by  Schneider  (1902:77), 
D.  serrata  Linstow  (1901:288)  evidently  does  not  belong  to  the  genus  at  all. 
But  with  none  of  these  could  the  material  studied  in  connection  with  the  present 
description  be  alligned.  Altho  it  bears  resemblances  in  individual  points  to 
B.  cohaerens  and  to  B.  pachycephalus,  doubtless  owing  to  the  fact  that  these 
have  been  better  described  than  the  others,  including  B.  fallax,  and  closely 
approaches  B.  nylandicus,  yet  it  is  so  different  from  the  latter  that  it  is  con- 
sidered to  constitute  a  new  species. 

The  scolex  (Figs.  6-8,)  is  typical  in  that  it  is  composed  of  two  surficial  and 
almost  hemispherical  bothria  arranged  in  the  usual  manner.  These  are  well 
separated  not  only  posteriorly  from  the  strobila  but  laterally  from  each  other 
by  distinct  grooves  as  in  B.  nylandicus.  In  all  of  the  specimens  studied  the 
apertures  of  the  bothria,  usually  circular  in  shape  and  about  0.1mm.  in  diame- 
ter altho  in  a  few  cases  somewhat  elongated  dorsoventrally,  were  distinctly 
separate.  But  since,  as  shown  by  Schneider,  there  is  great  variation  in  the 
extent  of  fusion  of  the  two  apertures  owing  to  differences  in  degree  of  contrac- 
tion even  in  individual  species,  this  separation  is  not  considered  to  be  of  speci- 
fic, let  alone  generic,  value.  The  compressed  lumen  of  the  bothrium  has  a 
transverse  diameter  of  0.3mm.;  while  the  other  measurements  of  the  scolex 
are  as  given  in  the  table  below.  The  short  unsegmented  region  between  the 
scolex  and  the  first  set  of  genitalia,  which  has  a  length  of  about  1.5mm.,  may 
be  considered  to  be  a  neck.  Excepting  for  the  openings  of  the  reproductive 
organs  and  the  protruded  cirri,  there  are  no  external  indications  of  segmenta- 
tion. Internally  this  is  also  the  case  as  regards  the  vitellaria  and  testes,  which 
are  both  strictly  continuous  from  proglottis  (set  of  genital  organs)  to  proglot- 
tis, as  in  the  genus  Bothriocephalus  (vide  infra).  The  strobila,  which  is  quite 
uniform  in  diameter  from  the  region  close  behind  the  scolex,  is  about  one-half 
as  thick  as  broad  and  sUghtly  more  convex  ventrally  than  dorsally,  as  in  B. 
nylandicus.    None  of  the  specimens  at  hand  were  complete  posteriorly.    The 


353] 


PSEUDOPHYLLIDEA  FROM  FISHES— COOPER 


65 


following  table  gives  measurements  of  the  three  largest  specimens  of  the  ma- 
terial studied : 


Length 

Length  of  scolex 

Length  of  bothria 

Breadth  of  scolex 

Depth  of  scolex 

Width  of  strobila  just  behind  scolex 

Maximum  breadth 

Average  breadth 

Depth  at  middle       


45mm. 

38mm 

0.55 

0.59 

0.64 

0.72 

0.74 

0.76 

0.90 

0.94 

0.87 

0.87 

L34 

1.34 

1.16 

1.16 

0.55 

0.50 

21mm. 
0.37 
0.66 
0.72 
1.02 
0.74 
1.60 
1.2 
0.61 


The  cuticula  is  about  5/x  in  thickness  not  only  over  the  general  surface  of 
the  strobila  but  also  in  the  interior  of  the  bothria.  In  the  latter  situation  it 
is  divided  into  two  layers  comparable  to  those  described  by  Schneider  (1902a: 
75)  for  B.  nylandicus:  an  outer,  occupying  about  three-fifths  of  the  whole 
thickness  and  made  up  of  comparatively  long  comidia  or  pseudocilia,  and 
an  inner,  quite  darkly  staining  stratum.  Whereas  Schneider  stated  that 
"Diese  Harchen  finden  sich  iiberall  auf  der  ganzen  Oberflache  des  Cestoden 
mit  alleiniger  Ausnahme  der  beiden  Hohlraume  in  den  Saugnapfen  und  der 
Rinne,  welche  den  Scolex  vom  Rumpfe  scheidet, "  the  writer  found  that  these 
were  the  very  places  the  two  chief  layers  were  best  seen. 

The  musculature  is  quite  similar  to  that  of  B.  nylandicus  as  described  by 
Schneider.  All  of  the  series  are  about  equally,  but  none  strongly,  developed 
and  each  consists  of  isolated  fibres.  The  arrangement  of  the  fibres  in  the 
scolex  is  quite  like  that  of  Clestobothrium  crassiceps,  there  being,  however,  no 
sphincters  controlling  the  openings  of  the  bothria. 

The  main  longitudinal  nerves  are  situated  in  the  median  frontal  plane  and 
about  two-ninths  of  the  transverse  diameter  of  the  strobila  from  the  margins, 
posteriorly  as  well  as  in  the  neck  region.  In  transverse  sections  each  strand 
varies  considerably  in  size  and  shape,  but  it  is  constantly  considerably  com- 
pressed and  has  a  transverse  diameter  of  from  15  to  20)Lt.  Anteriorly  the  system 
differs  greatly  from  that  of  B.  nylandicus.  In  the  latter,  according  to  Schnei- 
der, the  chief  strands  bend  outwardly  at  enlargements  in  the  region  between  the 
scolex  and  body ;  and  from  each  of  these  nerves  are  given  off  to  the  neighboring 
bothria  and  one  main  branch  towards  the  tip  of  the  region  to  unite  with  its 
fellow  of  the  opposite  side,  thus  forming  a  commissure  which  is  bowed  forward. 
In  this  species  each  main  trunk  divides  from  0.25  to  0.40mm.  behind  the  poster- 
ior borders  of  the  bothria  into  two  branches  of  equal  size  which  continue  for- 
ward in  a  strictly  sagittal  plane  as  they  gradually  enlarge.  At  about  the  mid- 
dle of  the  bothria  each  of  these  four  trunks  gives  off  large  branches  to  the 
lateral  walls  of  the  former,  and  then,  while  approaching  the  median  line  and 
partly  fusing  with  its  fellow  of  the  opposite  surface,  sends  off  several  small 
branches  to  those  on  the  other  side.  The  commissure  is,  therefore,  not  single 
but  composed  of  a  number  of  transverse  connectives  of  varying  size.    The 


66  ILLINOIS  BIOLOGICAL  MONOGRAPHS  [354 

transverse  ridge  between  the  bothria,  which  represents  the  tip  of  the  scolex, 
is  also  supplied  with  a  number  of  small  nerves  from  this  irregular  commissure. 

In  ripe  proglottides  there  are  four  main  longitudinal  excretory  vessels 
situated  roughly  in  the  median  frontal  plane,  two  at  the  extreme  margins 
of  the  medulla  and  two  just  within  the  nerve  strands.  Farther  forward  these 
divide  into  three  on  each  side.  The  middle  one  of  each  lateral  trio  then  divides 
dorsoventrally  into  two,  while  the  innermost  pair  gradually  diminishes  in  size 
and  are  soon  lost.  This  leaves  three  on  each  side,  arranged  as  a  triangle  with 
the  base  towards  the  median  line  and  the  apex  outward.  They  pass  into  the 
scolex  and  anastomose  to  form  an  irregular  plexus.  But  this  arrangement  of 
the  main  vessels  is  attended  with  a  good  deal  of  irregularity;  nor  is  it  the  same 
on  both  sides  of  the  median  line.  For  B.  nylandicus  Schneider  described  only 
two  main  longitudinal  trunks  "which  divide  anteriorly  into  several  canals  and 
form  numerous  coils,  especially  in  the  suckers. "  The  excretory  system  of  B. 
fallax  according  to  Liihe  (1900b  :257)  is  like  that  described  here  in  that  there 
is  a  triangle  of  vessels  on  each  side  anastomosing  with  each  other  and  with  the 
nearest  ones  of  the  opposite  side;  but  in  adition  it  shows  two  other  vessels 
which  "...  verlaufen  im  Gegensatz  zu  den  diinnwandigen  Gefassen  des 
Plexus  im  Inneren  der  Markschicht,  in  der  frontalen  Medianebene,  und  zwar 
der  eine  nach  innen,  der  andere  nach  aussen  vom  Langsnervenstamm.  Letzter- 
er  erinnert  seiner  Lage  nach  an  die  Verhaltnisse  bei  den  Dibothriocephalinen, 
insofem  als  die  Mehrzahl  der  Hodenblaschen  nach  aussen  von  ihm  liegt." 
It  will  also  be  seen  that  the  arrangement  of  the  excretory  vessels  in  this  species 
is  quite  different  from  that  described  by  Linstow  (1904:308)  for  B.  pachycepha- 
lus  Linstow,  in  which  species  there  are  fourteen  main  vessels  situated  in  the 
cortical  parenchyma  among  the  longitudinal  muscles.  None  of  the  specimens 
were  complete  posteriorly  so  that  the  disposition  of  the  system  in  the  true 
posterior  end  was  not  determined. 

The  reproductive  organs  appear  about  1.5mm.  behind  the  scolex  almost 
completely  developed.  Thei^  openings  are  in  the  median  line  and,  unlike 
B.  sturionis  Duvemoy,  all  on  the  ventral  surface,  that  is,  on  the  same  surface 
towards  which  the  ovarian  isthmus  is  situated  (cf.  B.  fallax  Liihe,  1900:10  and 
Cyathocephalus  americanus,  p.  57).  Furthermore,  while  the  male  and  female 
openings  are  from  0.09  to  0.22mm.  apart,  the  sets  of  genitalia  up  to  66  in  num- 
be,  are  0.55  to  0.65mm.  apart  in  the  longitudinal  direction,  which  distances 
are,  however,  of  no  great  specific  value  owing  to  the  different  degrees  of  con- 
traction and  relaxation  of  the  strobila.  The  female  genital  cloaca  is  an  irregu- 
larly circular  opening  into  which  the  vagina  opens  constantly  close  behind  the 
uterus,  as  in  B.  nylattdicus,  but  in  the  median  Une,  the  uterine  orifice  being  in 
this  case  the  one  which  is  not  exactly  in  line  with  that  of  the  vagina  and  the 
cirrus  but  alternates  irregularly  from  side  to  side.  There  is  a  weakly  developed 
sphincter  surrounding  the  common  female  cloaca.  It  seems,  however,  to  be 
at  least  partly  confined  to  the  vaginal  opening  rather  than  to  that  of  the  uterus. 

As  in  B.  nylandicus,  B.  pachycephalus  and  B.  cohaerens  the  testes  are 
situated  in  the  medullary  region  and  in  two  narrow  lateral  fields  continuous 


355]  PSEUDOPHYLLIDEA  FROM  FISHES— COOPER  67 

from  proglottis  to  proglottis.  As  a  matter  of  fact,  they  are  confined  to  the 
areas  between  the  two  pairs  of  the  four  main  longitudinal  excretory  trunks 
mentioned  above.  They  are  usually  almost  spherical  in  shape  with  maximum 
diameters  of  80  to  100/n.  Transverse  and  sagittal  sections  show  that,  owing  to 
the  large  size  of  the  median  reproductive  organs,  especially  the  large  uterus, 
and  their  consequent  inability  to  expand  laterally,  they  are  arranged  in  two 
pseudostrata  which  occupy  the  whole  of  the  dorsoventral  diameter  of  the  medul- 
la of  the  regions  in  question.  These  two  tiers  are,  however,  not  nearly  as 
extensive  as  in  B.  pachycephdus  Linstow  (1904:308,  Fig.  26).  The  vas  deferens 
is  in  the  form  of  a  narrow  mass  of  coils,  situated  immediately  anterodorsal  to 
the  cirrus-sac  or  slightly  to  one  side,  depending  on  the  amoimt  of  distension 
and  consequent  approximation  of  the  uterus  of  the  same  proglottis  to  that  of 
the  proglottis  ahead.  It  also  extends  to  the  dorsal  wall  of  the  medulla;  and 
its  diameter  is  about  30^.  Just  within  the  cirrus-sac  the  vas  deferens  is  sur- 
rounded for  a  short  distance  by  radiating  gland-like  ceUs,  reminding  one  of 
those  outside  of  the  pouch  in  C.  americanus.  But  there  are  no  such  cells  out- 
side of  the  cirrus-sac  as  described  for  B.  nylandicus  by  Schneider.  Then  it 
gradually  diminishes  from  a  diameter  of  35)u  in  the  ejaculatory  region,  which 
immediately  follows,  or  perhaps  includes  the  glandular  region,  to  about  20/a 
at  the  middle  of  the  sac.  From  this  point  it  enlarges  quickly  and  takes  on  the 
cuticula  and  a  series  of  circular  muscular  fibres  to  form  the  cirrus  proper  which 
in  the  distal  portion  of  the  pouch  may  attain  a  diameter  of  SOju.  The  extended 
cirrus  has  a  maximum  length  of  about  60/x  and  diameter  of  85m.  The  cirrus-sac 
is  oval  in  shape,  the  smaller  end  being  outward  and  the  major  axis  at  right 
angles  to  the  surface.  Its  depth  is  0.25mm.  while  its  diameter  is  0.17mm. 
As  in  C.  americanus  its  muscular  walls  are  only  weakly  developed  and  hence 
not  very  distinctly  separated  from  the  parenchymatous  tissue  within  and  with- 
out. Apart  from  the  duct  the  contents  of  the  pouch  consists  of  numerous 
parenchymatous  cells  and  retractor  muscles,  the  whole  forming  a  quite  compact 
structure. 

Just  within  the  medulla  the  vagina  turns  backward  and  continues  ventrally 
and  posteriorly  with  a  few  coils  toward  the  ovarian  isthmus.  Whereas  its 
diameter  is  30)u  near  its  opening,  half  way  along  its  course  this  is  reduced  to 
10/ii  and  enlarged  again  to  40  to  60/i  to  form  the  seminal  receptacle.  Close 
behind  and  somewhat  dorsal  to  the  isthmus  it  again  becomes  sharply  restricted 
to  10/i  to  form  the  spermiduct.  Its  whole  course  is  quite  as  described  for  B. 
nylandicus]  but  in  the  latter  there  is  evidently  no  enlargement  to  form  a  seminal 
receptacle  or  it  was  overlooked  by  Schneider,  as  indicated  in  his  statement: 
"  Sie  passiert  gleichfalls  auf  dem  kiirzesten  Wege  die  Subcuticularschicht  imd 
die  Muskelschichten,  biegt  dann  in  stumpfem  Winkel  nach  hinten  lun  und 
zieht,  immer  enger  werdend,  gegen  den  Ovidukt  hin.  In  der  Nahe  des  Eileiters 
wird  sie  so  eng  imd  diiniiwandig,  dass  die  EinmundungssteUe  nicht  genau 
festgestellt  werden  konnte."  The  ovary  is  like  that  of  B.  nylandicus  in 
that  it  is  crescentic  in  shape,  the  tubulolobular  wings  extending  to  the  dorsal 
musculature  and  surroimding  the  uterine  coils.    It  is,  furthermore,  comparable 


68  ILLIXOIS  BIOLOGICAL  MONOGRAPHS  [356 

to  C  americanus  in  that  these  wings  also  pass  forward  from  the  isthmus — ^but 
only  halfway  along  the  sides  of  the  uterus — and  that  the  median  region  of  the 
latter  is  spherical  and  somewhat  larger  than  the  lateral  portions.  From  the 
anterodorsal  aspect  of  this  enlargement,  which  has  a  diameter  of  about  0.1mm., 
the  oxiduct  arises  as  described  and  figured  for  B.  nylandicus.  The  diameter  of 
the  oocapt  is  about  25/i,  while  that  of  the  oviduct  beyond  its  point  of  union 
with  the  spermiduct  is  from  15  to  20/i.  The  common  vitelline  duct,  formed  by 
the  union  close  within  the  ventral  musculature  of  a  right  and  left  duct,  has  a 
diamxter  of  30^  when  filled  with  the  yolk  cells.  The  whole  of  the  common 
duct,  0.12mm.  in  length,  acts  as  a  vitelline  reservoir,  while  the  right  and  left 
ducts  usually  contain  a  good  deal  of  yolk  close  to  their  jimction.  As  in  B. 
nylandicus  the  vitelline  follicles  are  arranged  in  two  lateral  fields  in  the  cortical 
parenchyma,  which  are  not  only  so  restricted  as  to  leave  wide  median  areas 
free  of  them  dorsally  and  ventrally  but  are  continuous  at  the  margins  of  the 
strobila  as  well  as  from  proglottis  to  proglottis.  Like  the  testes  they  are  spheri- 
cal in  shape,  closely  arranged,  and  have  maximum  diameters  of  60/bL  The 
shell-gland,  located  just  beyond  the  point  of  imion  of  the  common  vitelline  duct 
with  the  oviduct,  is  so  weakly  developed  that  it  is  all  but  absent.  The  opening 
of  the  common  vitelline  duct  into  the  oviduct  was  not  foimd  to  be  "from  the 
right  side"  as  in  5.  nylandicus  but  irregularly  from  either  side.  Nor  was  there 
seen  any  distinct  enlargement  of  the  oviduct  in  the  region  of  the  ootype. 

The  first  portion  of  the  uterus  is  very  thin- walled,  and,  especially  when  free 
of  eggs,  quite  distinct  from  the  distal  portion  which  attains  a  diameter  of  0.25 
mm.  The  whole  duct  is  so  voluminous  when  filled  with  eggs  that  it  occupies 
almost  the  whole  of  the  medullar}'  region  of  the  proglottis  and  hence  more  than 
one-third  of  the  transverse  diameter  and  closely  approximates  that  of  the 
proglottides  ahead  and  behind,  thus  crowding  the  other  organs  almost  to  the 
point  of  obliteration — and  this  in  spite  of  the  fact  that  its  coils,  mostly  ar- 
ranged in  the  sagittal  direction,  are  ver>'  close  together.  The  distal  end  of  the 
duct  gradually  narrows  down  in  passing  ventrally  to  a  diameter  of  from  35  to 
45^  as  it  pierces  the  ventral  musculatiure  to  open  ahead  of  the  vagina  as  above 
mentioned.  No  special  enlargement  of  the  tube  just  before  its  opening,  such 
as  was  described  for  B.  nylandicus  is  present  in  this  form;  but  a  considerable 
length  of  the  proximal  portion  of  the  duct  is  surrounded  by  glandular  cells 
quite  similar  to  those  of  C.  americanus  (cf.  p.  61). 

The  maximum  dimensions  of  the  eggs  are  36  by  24/*  as  compared  to  40  by 
25m  in  B.  nylandicus. 

As  the  above  description  indicates,  this  form  comes  closest  to  B.  nylandicus 
Schneider,  but  it  differs  from  that  species  in  the  following  important  points: 
It  is  considerably  larger;  the  cuticula  lining  the  bothria  is  the  same  as  that 
covering  the  general  surface  cf  the  strobila;  the  number  and  arrangement  of 
the  excretory  vessels  are  quite  different;  the  structxire  of  the  nervous  system 
especially  anteriorly  is  radically  different;  there  are  more  than  twice  as  many 
sets  of  genitaha;  there  are  no  gland-like  ceUs  just  outside  of  the  drrus-sac; 
the  vagina  is  expanded  proximally  into  an  elongated  seminal  vesicle;  the  open- 


357]  PSEUDOPHYLLIDEA  FROM  FISHES— COOPER  69 

ing  of  the  common  vitelline  duct  into  the  oviduct  is  not  from  the  right  side  only 
but  from  either  side;  the  opening  of  the  uterus,  and  not  that  of  the  vagina,  is 
not  strictly  median  but  alternating  irregularly  from  side  to  side,  while  there  is 
no  enlargement  of  the  uterus  just  before  its  opening;  and  finally,  but  of  least 
importance,  there  is  no  fusion  of  the  bothrial  apertures.  Consequently  it 
seems  fitting  to  consider  this  form  a  new  species. 

The  material  studied  consisted  of  two  somev/hat  fragmentary  lots,  Nos.  205 
and  206  of  the  writer's  collection,  from  Pseudopleuronectes  americanus  (Wal- 
baum),  the  winter  floimder. 


70  ILLINOIS  BIOLOGICAL  MONOGRAPHS  [358 


MARSIPOMETRINAE  Cooper  1917 

Scolex  with  two  typical  and  fairly  deep  bothria  and  a  terminal  disc.  Exter- 
nal segmentation  very  distinct  and  regular.  Opening  of  cirrus  and  vagina 
marginal,  irregularly  alternating;  uterus-opening  surficial,  ventral,  at  the  same 
level  with  the  genital  cloaca  or  very  slightly  behind  it.  Only  one  set  of  gen- 
italia in  each  proglottis.  Testes  in  medulla  between  the  nerve  strands.  Mus- 
cular vesicula  seminalis  outside  of  the  cirrus-sac  absent.  Receptaculum 
seminis  large,  sharply  separated  from  the  spermiduct.  Ovary  not  exactly  in 
the  median  line  but  slightly  approaching  the  margin  bearing  the  genital  cloaca, 
ventral,  as  is  the  shell-gland.  Uterus  in  the  form  of  a  sac  developed  by  the  en- 
largement inwardly  of  that  portion  of  the  duct  passing  thru  the  cortical  paren- 
chyma.   Eggs  without  opercula. 

Type  genus:  Marsipometra  Cooper. 

As  regards  the  general  form  of  the  scolex  and  the  facts  that  the  genital  cloaca 
is  marginal  and  that  a  vesicula  seminalis  is  absent,  Marsipometra  comes  closest 
to  the  Triaenophorinae;  otherwise,  however,  it  is  related  to  other  subfamilies. 
External  segmentation  is  distinct  and  very  regular,  a  neck  being  present  as  in 
Diphyllobothrium  and  Bothridiimi  of  the  Diphyllobothriinae.  The  uterus- 
opening  is  at  the  same  level  with  the  genital  cloaca,  and  not  ahead  of  it  as  in 
the  Triaenophorinae.  Furthermore,  as  in  most  of  the  subfamilies  there  is 
only  one  set  of  genitalia  in  each  proglottis.  The  testes  are  situated  in  the  medulla 
between  the  nerve  strands  as  in  the  Haplobothriinae.  Unlike  the  structure  in 
the  Triaenophorinae,  the  receptaculum  seminis  is  large  and  sharply  separated 
from  its  continuation,  the  spermiduct,  which  also  obtains  for  the  Ligulinae, 
Haplobothriinae,  Diphyllobothriinae  and  Cyathocephalus.  The  ovary  is 
comparable  to  that  of  Triaenophorus,  Anchistrocephalus  and  Anonchocephalus 
(cf .  Liihe,  1902 :325)  in  that  it  is  not  exactly  in  the  median  line  but  situated 
towards  the  margin  bearing  the  genital  cloaca.  As  in  the  Triaenophorinae, 
however,  the  uterus  "nie  die  sogenannte  Rosettenform  bildend,  vor  seiner 
Miindung  meist  etwas  erweitert,  ohne  dass  indessen  diese  Erweiterung  ver- 
haltnissmassig  so  betrachtUch  ist,  wie  die  sogenannte  Uterushohle  der  meisten 
Ptychobothriiden. "  This  latter  difference  is  further  emphasized  by  the  fact 
that  at  no  stage  in  its  development  is  the  beginning  of  the  uterus,  which  might 
be  considered  at  first  sight  to  be  a  true  uterine  duct,  sharply  separated  from  the 
enlarged  portion  as  in  the  Ptychobothriidae.  The  outstanding  feature  that 
the  eggs  are  nonoperculate  has  been  noted  imder  the  remarks  on  the  family. 

MARSIPOMETRA  Cooper  1917 

Dibothrium  Linton  1897 

Bothriotaenia  Ariola  1900 

Scolex  unarmed,  sagittate.  Neck  present;  strobila  flat,  ribbon-shaped: 
proglottides  almost  rectangular,  posterior  borders  only  sUghtly  projecting. 


359]  PSEU DOPEY LLIDEA  FROM  FISHES— COOPER  71 

Nerve  strands  far  towards  the  margins,  dorsal  to  the  cirrus-sac  and  vagina. 
Testes  in  two  lateral  fields  united  ahead  of  and  behind  the  uterus-sac  and 
central  genital  ducts.  Vas  deferens  much  coiled  proximally,  only  weakly  so 
close  to  the  cirrus-sac.  Receptaculum  seminis  very  long.  Ovary  reniform, 
wings  tubulolobular,  isthmus  thick.  Shell-gland  not  in  the  middle  of  the 
genital  complex  but  towards  the  cloaca,  ahead  of  the  ovary.  Vitelline  follicles 
numerous,  not  in  two  lateral  fields  but  continuous  from  side  to  side  in  the 
anterior  and  posterior  regions  of  the  proglottis,  situated  among  the  body 
muscles.  Uterus-sac  pouched,  occup)ang  the  whole  of  the  medulla  dorsoven- 
trally  but  not  transversely.  Uterus  opening  towards  the  margin  bearing  the 
genital  cloaca. —  /xapcnTriov  a  Kttle  pouch;  ixrjrpa  the  uterus. 

Type  species:  M.  hastata  Linton. 

Attention  is  here  called  to  the  great  similarity  between  Marsipometra  and 
Haplobothrium  in  that  each  is  found  in  an  isolated  genus  of  fishes,  respectively 
Polyodon  and  Amia,  which  in  turn  are  relegated  to  isolated  famihes  and  orders. 
As  suggested  previously  by  the  writer  (1914)  in  dealing  with  Haplobothrium, 
the  unique  and  generahzed  nature  of  these  two  genera  is  doubtless  due  to  the 
great  age  of  their  respective  hosts.  On  account  of  the  fact  that  it  has  a  typical 
bothriocephalid  scolex,  Marsipometra  would  seem  to  be  the  yoimger  of  the 
two,  for  evidently  a  longer  period  of  time  must  have  been  required  for  the 
development  of  the  pecuhar  trypanorhynchous  scolex  and  method  of  segmen- 
tation of  Haplobothrium,  if  indeed  both  are  not  due  to  extreme  degeneration 
comparatively  speaking. 


MARSIPOMETRA  HASTATA  (Linton  1898) 
[Figs.  4,  5,  46,  47,  68,  83,  100,  101] 


1898 

Dibothriutn  hastatutn 

Linton 

1898:431 

1900 

Bothriotaenia  hastata 

Ariola 

1900:440 

1917 

Marsipometra  hastata 

Cooper 

1917:36 

Specific  diagnosis:  With  the  characters  of  the  genus.  Medium  sized  ces- 
todes  up  to  a  length  of  1 10mm.  with  a  maximum  breadth  of  3nim.  at  the  middle. 
Scolex  with  deep  bothria  and  prominent  posterior  borders,  1.5  to  2.8mm. 
in  length,  0.5  to  1.8mm.  in  width  anteriorly  and  1.3  to  2.0  posteriorly.  Sub- 
cylindrical  neck,  0.8  to  1.5mm.  wide.  First  segments  very  short  and  wide, 
middle  much  broader  than  long  and  rectangular  in  outline,  posterior  ones 
quadrate  to  slightly  longer  than  broad.    Whole  strobila  much  depressed. 

Cuticula  5/i  in  thickness,  subcuticula  40  to  50/z.  Calcareous  bodies  18 
by  13/1.  Longitudinal  musculature  weakly  developed,  that  of  scolex  strong. 
Nerve  strands  15  to  25/x  in  diameter.  Four  main  excretory  vessels  in  the 
strobila. 

Genital  cloaca  40  to  60/i  in  depth,  at  the  middle  of  the  margin  of  the  proglot- 
tis, irregularly  alternating;  hermaphroditic  duct  present,  also  sphincter  cloacae. 
Vagina  opens  immediately  ahead  of  the  cirrus. 


72 


ILLINOIS  BIOLOGICAL  MONOGRAPHS 


[360 


Testes  ellipsoidal,  60  to  90/i  in  diameter,  80  to  120  in  number,  arranged  in  a 
single  layer  in  the  medulla  and  interrupted  only  centrally.  Vas  deferens  a 
circular  mass  of  coils,  0.25  to  0.30mm.  in  diameter  dorsal  to  the  uterus-sac, 
or  to  one  side  of  it.  Seminal  vesicle  within  the  cirrus-sac,  50  to  60n  in  diameter; 
cirrus  proper  slender,  0.20mm.  in  length,  8  to  15^t  in  diameter.  Cirrus-sac 
elongate,  flask-shaped,  0.35mm.  in  length,  110/x  in  maximum  diameter. 

Vagina  15  to  20ju  in  diameter;  passes  to  median  line  ventrally,  then  dorsal 
to  the  uterus.  Receptaculimi  seminis  median,  90/x  in  diameter.  Ovary  reni- 
form,  tubulolobular,  0.45mm.  wide  and  0.18  long;  isthmus  thick,  ventral. 
Oocapt  40/i  long  and  18  in  diameter.  Two  ventral  vitelline  ducts;  common 
vitelline  duct  20/i  in  diameter.  Vitelline  follicles  irregular  in  shape  and  size, 
forming  a  continuous  layer  around  the  proglottis  excepting  for  median  circular 
areas  dorsally  and  ventrally.  Shell-gland  small,  compact,  115  by  55/i.  Uterine 
duct  with  only  a  few  dorsoventral  coils  near  the  median  line.  Uterus-sac 
circular  in  outline,  1.0mm.  in  diameter,  divided  by  deep  incisions  into  5  to  8 
pouches;  openings  opjwsite  the  genital  cloaca  or  slightly  behind  its  level  in 
gravid  proglottides  almost  in  the  medial  line. 

Eggs,  45  by  36/x. 

Habitat:  Intestine  of  host. 


HOST 

LOCALITY 

COLLECTOR 

AUTHORITY 

Polyodon  spathula 

Ohio  R.,  Wash- 

E. Linton 

Linton           1898:431 

(type  host) 

ington,  Pa. 

»        » 

111.  R.,  Beards- 

H.  J.  Vancleave 

Cooper  (the  present 

town,  111. 

paper) 

f>        )> 

L.  des  Allemands, 
Georgia 

H.  B.  Ward 

>i 

»        » 

Mississippi  R., 
Keokuk,  Iowa 

H.  B.Ward 

n 

»        » 

Mississippi  R., 
Fairport,  Iowa 

H.  B.  Ward 

» 

T>'pe  specimen:  No.  4724,  Collection  of  the  United  States  National  Museum. 
Type  locahty:  Ohio  River,  Washington,  Pennsylvania. 

This  species  was  originally  described  by  Linton  but  with  so  little  attention 
to  the  internal  anatomy  that  up  to  the  present  it  has  remained  pretty  much  a 
species  inquirenda  et  incerta  sedis,  as  pointed  out  by  Liihe  (1899c:40;  1900a: 
106);  altho  Ariola  (1900:440)  placed  it  in  the  now  obsolete  genus  Bothriotaenia 
RailHet. 

Linton  described  the  color  of  the  living  forms  as  "...  at  first  lemon- 
yellow;  after  lying  in  water  for  a  few  minutes  the  bodies  become  colorless  or 
faintly  bluish  translucent,  while  the  heads  remained  yellowish. "  Regarding 
their  method  of  attachment  he  said:  "Two  pits  were  found  excavated  in  the 
mucous  and  submucous  layers  of  the  pylorus  near  the  spiral  valve,  in  which  the 
heads  of  a  nimiber  of  Dibothria  were  inserted.    The  length  of  the  worm  was  re- 


361] 


PSEUDOPHYLLIDEA  FROM  FISHES— COOPER 


73 


corded  by  the  same  writer  as  from  25  to  TSmin.,  while  the  maximum  breadth 
was  2.7mm.  As  shown  in  the  table  below,  the  largest  examined  by  the  writer 
was  one  110mm.  in  length  with  a  m^aximum  breadth  of  3mm.,  which,  however, 
showed  the  characteristic  opaque  white  uterus-sac  filled  with  eggs  in  only 
the  last  eight  proglottides.  The  scolex  (Figs.  4,  5)  and  strobila  are,  as 
described  by  Linton,  "...  sagittate  (when  at  rest  and  contracted),  terminated 
anteriorly  with  a  button  shaped  tip  [the  terminal  disc]  which  is  bluntly  rounded 
in  front  and  marked  off  from  the  remainder  of  the  head  by  a  slight  constriction, 
in  life  angled  posteriorly;  pits  [bothria]  variable  in  life  but  usually  elliptical, 
often  with  anterior  margin  acuminate  and  sometimes  with  posterior  margin 
indistinct.  The  head  is  angled  posteriorly  both  laterally  [surficially]  and 
marginally,  presenting  a  quite  characteristic  appearance  in  the  living  worm. 
Neck  subcylindrical,  narrower  than  the  head.  The  segments  begin  some  dis- 
tance (6  or  8mm.)  back  of  the  head,  as  faint  transverse  hues.  The  first  distinct 
segments  are  closely  crowded  much  broader  than  long,  median  segments 
squarish  [but  still  much  broader  than  long],  posterior  segments  usually  a 
Uttle  longer  than  broad,  rectangular,  apparently  separating  rather  easily.  .  .  . 
Posterior  angles  of  the  segments  slightly  projecting.  ,  .  .  Outline  of  most 
of  the  strobilas  nearly  linear  and  about  the  same  breadth  as  the  head.  All 
the  segments  were  remarkably  regular  in  outline,  no  irregularities  being  ob- 
served." While  this  regularity  m  the  form  of  the  proglottides  and  in  their 
gradual  increase  in  size  anteriorly  and  change  of  shape  posteriorly  is  especially 
noteworthy  in  this  species,  the  WTiter  met  with  a  few  cases  of  intercalated  tri- 
angular and  aberrantly  subdivided  segments  in  the  material  studied.  It 
should  be  emphasized,  too,  that  the  whole  strobila  including  even  the  scolex 
is  constantly  much  flattened  dorsoventrally,  which  also  assists  in  giving  the 
worm  the  peculiar  diagrammatic  appearance  which  is  mentioned  below.  The 
following  table  gives  the  measurements  of  foiu-  specimens,  together  with  those 
by  Linton  in  the  first  two  colums  for  comparison: 


Length 

Length  of  scolex 

60mm. 

2.75 
1.8 

4Smm. 
1.85 

76mm. 
1.48 
0.60 
0.43 
1.35 
1.16 
0.87 
0.36 
0.75 
2.32 
1.5 
1.4 
2.38 

O.W. 

39mm. 
1.75 
0.55 
0.31 
1.31 
0.96 
0.88 
0.37 
0.46 
1.38 
0.85 
1.10 
1.38 
O.W. 

61mm. 
2.34 
0.73 
0.60 
1.83 
0.98 
1.40 
0.48 
0.80 
2.75 
0^90 
2'.85 
3.0 
Ale. 

110mm. 
2.01 

Width  term,  disc 

0.80 

Depth  term,  disc 

0.42 

Width  at  base 

2.0 

1.7 
1.3 

1.95 

Depth  at  base 

1.10 

Width  of  neck 

1.1 

1.52 

Depth  of  neck 

0.4 

0.35 

2.5 

0.55 

2.7 

0.68 

Length  middle  segs 

0.73 

Width  of  same 

2.44 

Length  post,  segs 

1.13 
2.0 

1.52 

Wikth  of  same 

2.44 

Maximum  breadth 

3.0 

Measured  in 

water 

alcohol 

Formol 

74  ILUNOIS  BIOLOGICAL  MONOGRAPHS  [3fi2 

The  cuticula,  5^1  in  thickness,  consists  of  two  layers  of  equal  thickness,  an 
outer  irregular  and  more  darkly  staining  layer,  which  is  sloughed  oflF  in  many 
places,  and  an  inner,  more  homogeneous  and  lighter  stratum  between  which 
the  outermost  portion  of  the  inner  layer  shows  as  a  dark  bounding  membrane. 
Altho  only  about  one-half  as  thick  on  the  outside  of  the  scolex  and  still  thinner 
on  the  inside  of  the  bothria,  it  is  not  modified  to  form  minute  spines  on  the 
edges  of  the  terminal  disc  nor  hinder  end  of  the  scolex  where  such  might  be 
expected  to  be  located.  Their  absence  also  on  the  posterior  borders  of  the 
proglottides  (cf.  Haplohothrium  glohidiforme)  is  not  surprising  since  these  pro- 
trude only  very  slightly.  The  subcuticula  varies  from  40  to  50/x  in  thickness 
and  is  made  up  of  narrow  elongated  cylindrical  cells  with  small  nuclei,  the  outer 
ends  of  which  are  dendritic  and  quite  separate  from  each  other  as  are  the  bodies 
themselves.  The  meshes  of  the  parenchyma  are  very  loose  and  open,  the  spaces 
being  large  and  the  strands  of  the  cytoplasmic  framework  considerably  nar- 
rower than  the  small  nuclei  which  are  located  as  usual  at  the  intersections  but 
surroimded  by  only  a  limited  amoimt  of  protoplasm.  Linton  stated  that, 
"The  segments  contain  numerous  calcareous  bodies,  which  exhibit  a  concen- 
tric structure. "  They  are  to  be  foimd  fairly  plentiful  in  all  parts  of  the  medulla 
and  cortex  and  even  among  the  subcuticular  cells.  They  are  eUiptical  or 
oval  in  outUne,  the  largest  ha\Tng  dimensions  of  18  by  13//. 

The  musculature  of  this  species,  excepting  that  of  the  scolex,  is  compara- 
tively weak,  no  one  series,  not  even  the  longitudinal,  being  especially  strong. 
All  groups  are  prominent,  in  that  they  consist  of  more  or  less  isolated  fibres 
quite  diagrarmnatically  arranged.  Their  conspicuousness  is,  indeed,  amplified 
by  the  fine  texture  of  the  parenchyma.  The  frontal  or  transverse  series  do 
not  form  a  compact  layer  closely  appUed  to  the  inside  of  the  longitudinal 
muscles  but,  as  shown  in  figure  83,  a  stratvim  of  varying  thickness;  owing  to  the 
degree  of  separation  of  the  fibres,  especially  laterally.  The  myoblastic  nuclei 
of  many  of  them  can  be  easily  seen.  The  sagittal  series  are,  however,  quite 
prominent,  and  equally  distributed  from  border  to  border  of  the  strobila. 
They  show  their  myoblastic  nuclei  and  surrounding  cytoplasm  very  clearly, 
reminding  one  of  the  dorsoventral  muscles  of  Abothrium  rugosum.  While  the 
fibres  of  both  these  series  are  only  sHghtly  more  numerous  opposite  the  posterior 
borders  of  the  proglottides,  where  they  form  more  or  less  distinct  septa,  they 
are  very  well  developed  in  the  neck  and  anterior  segments.  The  longitudinal 
muscles  form  only  a  single  layer  of  loosely  arranged  fascicles  of  irregular  size 
in  the  middle  and  posterior  segments,  but  in  the  neck  they  form  a  much  thicker 
stratum,  showing  no  distinct  bundles  and  occupying  the  whole  of  the  space 
between  the  transverse  muscles  and  the  subcuticular  nuclei.  Altho,  as  above 
mentioned,  the  posterior  borders  of  the  proglottides  are  not  very  prominent, 
there  is  a  representative  series  of  outer  longitudinal  muscles,  best  seen  in  the 
middle  segments  where  they  are  situated  close  to  the  longitudinal  cuticular 
fibres  with  which  they  are  easily  confused.  Concerning  the  latter  all  that 
need  be  said  is  that  they  are  well  developed  and  consist  of  isolated  fibres  which 
render  the  two  layers  all  the  more  visible. 


363]  PSEUDOPHYLLIDEA  FROM  FISHES—COOPER  75 

The  musculature  of  the  scolex  is,  as  might  be  judged  from  its  size  and  its 
shape,  very  powerful.  While  the  longitudinal  muscles  of  the  neck  merely 
enter  the  base  of  the  scolex,  the  transverse  and  sagittal  fibres  are  directly  con- 
tinuous with  the  circular  and  radial  fibres,  respectively,  of  the  latter.  Here, 
however,  the  radial  fibres  are  quite  separate  from  the  dorsoventral  fibres  with 
which  they  are  considered  to  be  homologous,  especially  laterally  where  they 
pass  from  the  cuticula  lining  the  bothria  to  the  sides  of  the  scolex  as  in  other 
bothriocephaUds  with  prominent  bothrial  walls.  Farther  forward  the  sagittal 
muscles  proper  passing  between  the  bothria  are  scarce,  their  function  being 
taken  over  by  the  very  numerous  and  closely  arranged  radial  fibres  which  are 
quite  as  plentiful  in  the  median  line  as  laterally.  In  the  terminal  disc  both 
transverse  and  dorsoventral  fibres  are  again  prominent,  while  the  radial  ones 
are  absent.  Posteriorly  the  latter  pass  dovm  along  the  sharp  edges  of  the 
beginning  of  the  neck.  Frontal  sections  demonstrate  the  presence  in  the  edge 
of  the  terminal  disc  as  well  as  in  the  posterior  borders  of  the  scolex  of  two  series 
of  longitudinal  arcuate  fibres  arranged  for  the  control  of  these  prominent  ridges. 
These  are  perhaps  modified  portions  of  the  outer  longitudinal  muscles  which 
are  very  numerous  in  the  scolex,  and  converge  in  the  anterior  portions  of  the 
edges  of  the  walls  of  the  bothria  to  become  attached  to  the  edge  of  the  terminal 
disc  at  the  four  respective  points. 

The  chief  nerve  strands,  from  15  to  25m  in  dorsoventral  diameter  and  from 
15  to  20m  in  lateral  diameter,  are  situated  far  towards  the  edges  of  the  medulla 
and  in  the  median  frontal  plane  or  somewhat  dorsally  (Fig,  83).  They  pass 
dorsal  to  the  junction  between  the  lateral  and  middle  thirds  of  the  cirrus-sac 
and  consequently  dorsal  to  the  vagina.  In  the  neck  they  are  located  in  the 
very  borders  of  the  medullary  parenchyma,  but  as  they  enter  the  base  of  the 
scolex  they  approach  the  median  line  somewhat.  As  they  pass  on  with  a  vary- 
ing diameter  towards  the  tip  of  the  scolex,  they  give  off  a  nmnber  of  branches 
to  the  walls  of  the  bothria  and  finally  enlarge  in  the  terminal  disc  to  form  two 
gangUa,  each  with  a  diameter  of  about  SO/x,  which  send  off  in  turn  numerous 
large  branches  to  the  immediate  neighborhood.  Each  of  these  ganglia  is 
divided  into  two  large  trunks  which,  however,  continue  only  a  very  short  dis- 
tance farther  forward  before  they  are  joined  by  two  commissures  to  their  fellows 
of  the  opposite  side  of  the  scolex  in  such  a  way  that  the  two  branches  of  the 
gangha  on  each  surface  of  the  scolex  are  connected.  In  frontal  sections  each 
of  these  commissures  is  seen  to  be  bowed  slightly  forward  into  the  tip  of  the 
terminal  disc  and  to  give  off  further  forward  on  each  side  a  large  branch  which 
passes  farther  into  the  latter. 

The  excretory  system  consists  of  a  varying  nmnber  of  vessels,  of  which  four 
pursue  a  more  or  less  constant  course  thruout  the  medulla  of  the  strobila. 
These  are  found  at  all  levels  in  transections  and  are  separated  from  each  other 
in  the  transverse  direction  by  different  distances.  The  outermost  two,  how- 
ever, are  slightly  larger  and  have  thinner  walls  than  the  innermost  pair.  They 
give  off  numerous  large  branches  and  are  connected  by  various  anastomoses 
with  each  other  and  the  more  peripheral  vessels.    In  the  neck  they  cannot  be 


76  ILUNOIS  BIOLOGICAL  MONOGRAPHS  [35* 

followed  as  well,  while  close  to  the  scolex  they  lose  their  identity  and  break  up 
into  a  plexus  of  very  small  vessels  which  ramifies  forward  thruout  the  latter. 
In  the  posterior  border  of  the  scolex,  however,  a  small  branch  on  each  side 
takes  a  straight  course  just  within  the  nerve  strand  for  a  short  distance. 
Flame-cells  are  quite  numerous  and  readily  discernible  especially  in  the  medul- 
lary parenchyma.  In  young  strobilas  where  no  segments  have  yat  been  lost, 
two  comparatively  large  excretory  vessels  pass  backward  to  the  posterior  end 
and  empty  into  a  small  narrow  terminal  vesicle.  This  in  a  larva  12.4mm.  in 
length  was  found  to  be  40/i  long  by  lOfi  wide,  while  the  diameter  of  the  excre- 
tory vessels  was  15/i. 

The  eaxUest  traces  of  the  reproductive  organs  in  the  form  of  a  transverse 
line  in  either  half  of  the  proglottis  (the  rudiments  of  the  vagina,  cirrus-sac  and 
lateral  portions  of  the  vas  deferens)  appear  from  4  to  10mm.  from  the  tip  of  the 
scolex,  while  the  first  eggs  are  seen  in  the  uterus-sacs  from  25  to  35mm.  from 
the  same  point.  The  development  of  all  of  the  genitalia  is  very  gradvial  and 
can  be  easily  followed  in  good  toto  preparations,  since  the  diagrammatic  nature 
of  the  worm,  above  mentioned,  extends  to  the  reproductive  system,  making 
this  species  an  ideal  one  for  study.  The  cirrus  and  vagina  open  into  a  common 
genital  cloaca,  which  is  situated  in  the  middle  of  the  margin  of  the  proglottis, 
while  the  utCTUs  opens  on  the  ventral  surface,  not  in  the  median  line  but  towards 
the  side  occupied  by  the  atrium.  The  cloacae  alternate  irregularly  from  side 
to  side,  from  one  to  ten  having  been  found  occupying  the  same  margin  in 
successive  proglottides.  The  following  figures  represent  the  number  of  such 
segments  before  the  genital  apertm-e  changes  to  the  other  side  in  the  fifth 
specimen  of  the  above  table:  1,  2,  1,  8,  1,  1,  1,  2,  2,  3,  3,  1,  2,  2,  10, 1, 1, 1,  3, 
3,  2,  2,  1,  4, 1, 1,  2, 2, 3, 2,  2, 3,  6,  6,  1, 1, 1, 1, 1, 3,  2, 1, 3, 3,  2— as  far  forward  as 
the  rudiments  could  be  conveniently  traced.  The  genital  cloaca  (Figs.  100, 101) 
is  elliptical  in  outline  when  viewed  from  the  side,  its  longer  diameter  being 
directed  dorsoventrally,  while  in  transverse  sections  it  is  squarish  in  outline. 
The  dorsoventral  diameter,  longitudinal  diameter  and  depth  are,  respectively, 
70  to  85/i,  40  to  55^1  and  40  to  60;i.  Into  the  middle  of  the  bottom  of  this 
depression  opens  the  hermaphroditic  duct  which  is  about  60/i  in  length,  into 
the  bottom  of  which  in  turn  opens  the  vagina  immediately  ahead  of  the  cirrus. 
Since  the  cirrus  proper  is  a  long  slender  tube  and  since  the  external  portion 
of  the  hermaphroditic  duct  is  usually  foimd  qmte  tightly  closed  and  the  end 
of  the  cirrus  turned  aroimd  toward  the  opening  of  the  vagina,  self-impregnation 
would  seem  to  be  quite  probable  in  this  species.  On  the  other  hand,  the  fact 
that  the  genital  cloaca  is  so  well  formed  and  fiurther  that  it  is  surrounded  by  a 
well  developed  sphincter  and  a  series  of  muscular  fibres  radiating  out  into  the 
surrounding  parenchjona,  as  shown  in  figures  100  and  101,  argue  in  favor  of  its 
use  in  cross-fertilization.  No  protruded  cirri  were  seen,  however,  in  the  material 
at  hand.    Perhaps  both  methods  of  fertilization  occur. 

The  testes  are  spherical  to  eUipsoidal  in  shape,  their  longest  diameters 
being  dorsoventral,  while  their  cross-sections  are  usually  circular  in  outline. 
In  segments  where  there  are  as  yet  only  a  few  eggs  in  the  uteri  their  dorsoven- 


365]  PSEUDOPHYLLIDEA  FROM  FISHES— COOPER  77 

tral  and  transverse  diameters  are,  respectively,  85  to  90)u  and  60  to  80^.  In 
the  anterior  and  posterior  ends  of  the  proglottis — they  are  not  continuous 
from  segment  to  segment  but  separated  by  the  aggregations  of  sagittal  and 
transverse  muscles  mentioned  above  as  forming  more  or  less  complete  septa — 
they  form  a  single  layer  situated  in  the  medulla  in  the  median  frontal  plane, 
but  are  widely  separated  in  the  middle  of  the  proglottis  by  the  central  genital 
organs  and  ducts,  especially  the  uterus-sac.  Their  number  ranges  from  80 
to  120  for  each  proglottis.  While  the  wall  of  the  testis  consists  of  a  very  thin 
m.embrane  from  which  nuclei  protrude  inwardly,  the  contents  are  such  as  to 
show  the  process  of  spermatogenesis  quite  clearly.  The  vas  deferens  forms 
a  circular  mass  of  coils,  0.25  to  0.30mm.  in  diameter,  applied  like  a  cap  to 
the  dorsal  side  of  the  developing  uterus-sac  and  thus  close  to  the  inner  end 
of  the  cirrus-sac.  When  the  uterus  becomes  gorged  \vith  eggs  it  is  pushed  aside 
somewhat  but  still  retains  similar  relations  with  one  of  the  pouches  of  the  for- 
mer, located  in  the  direction  of  the  genital  cloaca  (Fig.  68).  In  the  mass  of 
coils  the  duct  is  usually  distended  with  spermatozoa  to  a  diameter  of  40/t. 
It  gradually  narrows  down  to  a  diameter  of  15/x  before  entering  the  cirrus- 
sac,  before  which  there  is,  however,  no  seminal  vesicle.  But  within  the  pouch 
the  vas  deferens  enlarges  to  form  a  large  seminal  vesicle,  which  \\ith  a  diameter 
of  from  50  to  60/i  takes  only  a  few  coils  before  passing  on  as  the  cirrus  proper 
from  which  it  is  sharply  separated  (Fig.  101).  The  cirrus  is  a  slender  tube  from 
0.17  to  0.22mm.  in  length  within  the  pouch  and  from  15/i  in  diameter  nearest 
the  seminal  vesicle  to  8/x  at  its  opening.  It  is  lined  with  a  thin  cuticula  which 
is  circularly  cleft  in  its  proximal  one-third  but  almost  smooth  for  the  rest  of 
its  length,  nowhere,  however,  showing  anything  in  the  nature  of  an  armament. 
The  cirrus-sac  (Fig.  101)  is  an  elongated  flask-shaped  structure  with  a  maximum 
diameter  proximally  of  110/x  and  distally  of  40/x,  and  a  length  of  0.35mm.  The 
neck  of  the  organ  usually  shows  a  couple  of  dorsoventral  curves,  while  about 
20/i  of  its  distal  end  protrudes  into  the  hermaphroditic  duct.  Its  walls  are 
comparatively  thin  and  composed  of  an  irmer  layer  of  circular  muscles  and 
an  outer  weaker  and  much  less  compact  layer  of  longitudinal  fibres.  Apart 
from  the  seminal  vesicle  which  occupies  almost  the  whole  of  the  proximal  en- 
larged portion  and  the  narrow  cirrus,  the  contents  consist  of  only  a  limited 
amount  of  parenchymatous  tissue  and  a  very  few  feeble  retractor  muscles. 
The  whole  structure  of  the  cirrus-sac  is  in  fact  such  as  to  suggest  that  the 
function  is  that  of  an  organ  for  the  explusion  of  spermatozoa  rather  than  for 
the  emission  of  a  copulatory  organ;  altho  a  few  muscles  passing  from  the 
body  waU  around  the  cloaca  to  the  anterior  part  of  the  neck  of  the  sac  (Figs. 
100, 101)  would  seem  to  indicate  that  a  smaU  portion  at  least  of  the  cirrus  is 
protruded,  perhaps  during  self-fertilization. 

Altho  the  vagina  opens  into  the  hermaphroditic  duct  dkectly  ahead  of 
the  cirrus,  it  almost  immediately  curves  around  the  distal  portion  of  the 
cirrus -sac  to  the  antero  ventral  side  of  the  latter  which  it  follows  closely  towards 
the  median  line.  Close  to  the  wall  of  the  inner  end  of  the  cirrus-sac,  however, 
it  crosses  the  distal  coils  of  the  vas  deferens  towards  the  dorsal  sufrace  and 


78  ILLINOIS  BIOLOGICAL  MONOGRAPHS  [366 

skirts  the  uterus-sac.  When  it  reaches  the  median  line  above  the  sack  it  turns 
sharply  downward  and  backward.  The  vagina  has  a  diameter  of  from  15  to 
20/i  opposite  the  middle  of  the  cirrus-sac  and  is  lined  with  only  a  comparatively 
thin  layer  of  cuticula.  It  very  gradually  expands  after  crossing  the  inner 
end  of  the  cirrus-sac  to  form  a  much  elongated  and  very  spacious  receptaculum 
seminis,  the  diameter  of  which  close  to  its  inner  end  may  be  as  much  as  90/i. 
This  is  usually  fiUed  in  sections  with  spermatozoa,  a  stream  of  which  may 
often  be  seen  passing  on  into  the  spermiduct.  The  beginning  of  the  duct  is 
surrounded  by  a  poorly  developed  layer  of  circular  muscles  which  are  almost 
absent  from  the  inner  expanded  portion.  The  receptaculum  is  sharply  separa- 
ted from  the  spermiduct  which  has  a  diameter  of  only  15  to  20/i  and  a  length 
of  0.12mm.  The  latter  is  an  almost  straight  tube  passing  in  the  median  line 
from  the  more  dorsally  situated  receptaculum  to  its  point  of  union  with  the 
oviduct  close  to  the  ventral  wall  of  the  medulla  (Fig.  83).  It  shows  best  in 
transections  where  its  walls  are  seen  to  be  composed  of  an  epitheHum  of  cubical 
cells  lying  on  a  distinct  basement  membrane,  and  to  be  surroimded  with  a 
thick  layer  of  nuclei  and  extremely  few,  if  any,  muscle  fibres.  The  ovary 
(Figs.  68, 83)  is  a  somewhat  kidney-shaped  tubulolobular  organ  situated  in  the 
posterior  half  of  the  proglottis  behind  the  developing  uterus-sac  with  its  con- 
cavity directed  forward,  and  not  exactly  in  the  median  Une  but  sUghtly  ap- 
proaching the  cloaca.  It  averages  0.45mm.  in  width  by  0.18  in  length.  The 
isthmus,  which  is  almost  as  long  and  about  one-half  as  thick  as  the  wings,  is 
located  only  slightly  below  the  median  frontal  plane  of  the  medulla.  Ova 
from  the  same  have  a  diameter  of  from  20  to  25)u.  In  gravid  proglottides 
where  the  uterus  is  filled  with  eggs  only  a  small  portion  of  the  degenerating 
ovary  remains,  and  this  is  accommodated  between  the  two  hindermost  pouches 
of  the  uterus-sac.  The  oviduct  commences  in  the  median  line  anteroventral 
to  the  ovarian  isthmus  as  a  somewhat  cylindrical  oocapt,  40^t  in  length  by  18 
in  diameter  and  not  sharply  separated  from  the  rest  of  the  duct  (Fig.  83).  It 
passes  ventrally  with  a  diameter  of  20jli  for  about  SOju  before  being  joined  by 
the  spermiduct,  and  then  for  only  a  short  distance  farther  anterolaterally 
along  the  ventral  transverse  musculature  before  meeting  the  common  vitelline 
duct.  The  latter  is  formed  by  the  union  in  the  usual  manner  of  two  vitelline 
ducts  coming  from  the  lateral  regions  of  the  proglottis  along  the  ventral  wall 
of  the  medulla.  It  is  quite  short,  however,  and  usually  contains  only  a  limited 
amount  of  yolk,  its  diameter  being  at  the  most  only  20/x.  The  vitelline  foUicles 
(Fig.  83)  are  irregularly  eUipsoidal  in  shape,  and  situated  either  just  within 
the  transverse  muscles,  between  them  and  the  longitudinal  muscles,  among 
the  latter  or  even  sHghtly  outside  of  the  longitudinal  muscles.  While  they 
vary  considerably  in  size  and,  not  being  very  nimierous,  are  widely  spaced, 
their  average  maximum  diameter  is  about  50/x.  They  form  a  continuous  band 
completely  surrounding  the  medulla,  excepting  for  irregularly  circular  areas 
above  and  below  the  ventral  ducts  and  organs,  in  the  median  line,  but  are  not 
continuous  from  joint  to  joint.  On  the  whole  they  remind  one  of  the  vitellaria 
of  A.  crassum.    The  xmion  of  their  different  ductlets  can  be  easily  traced, 


3671  PSEUDOPHYLLIDEA  FROM  FISHES— COOPER  79 

especially  in  frontal  sections  of  younger  proglottides,  since  they  are  com- 
paratively large  and  hence  quite  distinct.    The  shell-gland  is  a  small  compact 
organ,  about  115^  in  width  by  55/i  in  length,  surrounding  the  oviduct  just 
beyond  the  entrance  of  the  vitelline  duct,  or  to  be  more  exact,  just  beyond  the 
first  turn  taken  by  the  latter  in  its  return  to  the  median  line  after  passing 
laterally,  as  above  stated.    It  is  thus  situated  ventrally  and  a  short  distance 
from  the  median  line.    Beyond  the  shell-gland  the  oviduct  continues  as  the 
uterine  duct  which  takes  only  a  few  dorsoventral  turns  near  the  median  line 
before  emptying  into  the  uterus-sac.    The  latter  is  formed  in  development 
by  the  gradual  enlargement  dorsally  of  that  portion  of  the  duct  which  traverses 
the  cortical  parenchyma  on  the  ventral  surface  of  the  proglottis.    Just  before 
eggs  appear  in  the  sac  this  part  of  the  tube  can  be  seen  in  transections  as  a 
spindle-shaped  dilatation,  whose  nucleated  epithelial  wall  is  surrounded  by 
a  thick  layer  of  nuclei,  the  whole  being,  however,  not  distinctly  separated  from 
the  proximal  portion  of  the  tube  (the  uterine  duct  of  older  stages)  at  a  constric- 
tion just  ^vithin  the  transverse  musculature.    In  proglottides  farther  ahead 
this  constriction  is  outside  of  the  transverse  muscles  in  the  cortex;  so  that  the 
uterus-sac  must  be  looked  upon,  then,  as  being  formed  by  a  gradual  enlarge- 
ment of  the  distal  end  of  the  uterus  as  it  becomes  filled  with  eggs  and  not  as 
a  sac  separated  in  the  rudiments  from  the  proximal  uterine  tract  as  in  the 
Ptychobothriidae.    In  one  case  where  only  5  or  6  eggs  appeared  in  the  limien 
the  uterus-sac  had  a  diameter  in  frontal  sections  of  80;u;  in  the  next  segment 
following  it  was  enlarged  in  all  directions,  somewhat  elliptical  in  outline,  with 
a  diameter  of  240/^;  in  the  next  still  larger;  and  in  the  fourth  somewhat  pointed 
anteriorly.     From  this  region  on  it  quickly  enlarges  until  finally  it  forms  a 
capacious  sac,  as  much  as  1.0mm.  in  diameter,  occupying  in  gravid  proglottides 
the  whole  of  the  dorsoventral  diameter  of  the  medulla  and  almost  all  of  the 
longitudinal  and  transverse  diameters.     In  transverse  sections  it  is  almost 
entire  in  outline,  while  in  frontal  sections  it  is  divided  into  from  5  to  8  large 
irregularly  shaped  lobes  or  diverticula,  the  hindermost  two  of  which  enclose 
the  remainder  of  the  ovar>'  and  the  central  connections  of  the  reproductive 
ducts,  as  above  mentioned.    Ventrally,   the  sac    is   funnel-shaped  towards 
the  small  opening  which  only  appears  when  the  proglottis  becomes  quite 
gravid.     Since  the  uterus-sacs,  even  the  most  gravid  ones,  are  not  situated 
exactly  in  the  median  line  but  towards  the  margins  bearing  the  genital  cloacae, 
the  openings  form  "   ...  a  zig-zag  line  of  minute  pores  [which]  traverses 
the  median  region  of  one  of  the  broad  faces  of  the  strobila,  each  pore  being 
near  the  middle  of  its  segment."    Linton  correctly  considered  them  to  be 
for  the  escape  of  the  eggs.    Anteriorly,  where  the  uterus-sacs  do  not  yet  con- 
tain eggs,  these  pores — in  reality  the  ventral  funnel-shaped  portions  of  the 
sacs — are  located  about  0.18mm.  on  each  side  of  the  median  line,  but  posterior- 
ly they  are  relatively  much  closer  together,  in  fact  almost  exactly  in  the  median 
line.     Furthermore,  they  are  situated  directly  opposite  or  slightly  behind  the 
level  of  the  genital  cloaca.    The  opening  is  formed  by  the  rupture  of  the  body 


80  ILUNOIS  BIOLOGICAL  MONOGRAPHS  [368 

wall  in  a  very  small  and  limited  area,  and  not  of  a  preformed  membrane  as 
in  the  Pt}"chobothriinae. 

Concerning  the  eggs  Linton  (p.  433)  said:  "The  ova  are  nearly  spherical, 
with  thin  shells.  They  are  about  0.04mm.  in  the  greatest  diameter. "  Those 
from  material  preserved  in  formalin  were  found  by  the  writer  to  be  sometimes 
spherical  in  shape  but  usually  ovoid  or  ellipsoid,  with  maximiun  dimensions 
in  the  latter  case  of  45  by  36;x.  Neither  in  sections  nor  in  preparations  of 
eggs  from  the  uterus  sacs  of  material  in  formol,  alcohol  or  cleared  in  oU  of 
wintergreen  were  opercula  to  be  found,  but  at  the  one  pole  of  the  egg  a  small 
boss  about  5m  in  diameter  which  is  of  ten  enlarged  to  form  a  distinct  projection 
or  appendage.  Altho  development  had  not  progressed  in  any  of  the  eggs 
studied  so  far  that  the  six  hooks  of  the  oncosphere  were  visible,  the  writer 
is  of  the  opinion  that  even  in  mature  eggs  no  opercula  would  be  found,  since 
its  almost  spherical  shape  and  the  presence  of  the  button-like  thickening  at 
one  pole  are  quite  like  conditions  in  the  nonoperculate  egg  of  Ahothrium  rugo- 
sum,  for  instance,  as  described  and  figured  by  Schauinsland  (1885:527)  and 
further,  since  in  the  egg  of  the  operculate  type,  as  in  that  of  D.  latum  or  of 
T.  nodulosus,  described  and  figured  by  the  same  writer,  the  operculum  is  present 
long  before  the  hexacanth  embryo  has  developed. 

As  regards  the  life-histor>'  of  this  species  nothing  is  as  yet  known.  It  is 
noteworthy,  however,  that  ver>'  yoimg  larvae,  such  as  shown  in  figures  46 
and  47,  can  be  easily  recognized  on  account  of  the  peculiar  character  of  the 
scolex,  so  that  it  would  not  seem  difficult  to  pick  them  out  of  the  intermediate 
host  whatever  that  may  be.  All  sizes  from  the  youngest  (Fig.  46)  to  the  lar- 
gest were  present  in  the  material  studied. 

The  material  of  this  species  consisted  of  Nos.  4724  and  4783  of  the  collection 
of  the  United  States  National  Museum,  Nos.  16.292,  16.421  and  17.11  of  the 
collection  of  the  University  of  Illinois  and  No.  154  of  the  writer's  collection, 
all  from  the  intestine  of  Polyodon  spathula,  the  paddlefish. 


369] 


PSEUDOPHYLLIDEA  FROM  PISHES— COOPER 


81 


TRIAENOPHORINAE  Liihe  1899 

Scolex  armed  or  unarmed,  always  with  two  typical  and  not  very  deep 
bothria,  ahead  of  which  the  flattened  termination  of  the  scolex  projects  more 
or  less  prominently  in  the  form  of  a  ring.  External  segmentation  present  or 
absent,  in  the  former  case  an  mijointed  neck  being  absent.  Opening  of  cirrus 
and  vagina  marginal,  irregularly  alternating;  uterus  opening  surficial,  ventral, 
ahead  of  the  marginal  genital  aperture.  Genital  apparatus  always  single 
in  each  proglottis.  No  muscular  bulb  (Eschricht's  body)  on  the  inner  end  of 
the  cirrus-sac.  Receptaculum  seminis  comparatively  smaU,  not  always  sharp- 
ly separated  from  the  narrow  inner  end  of  the  vagina.  Uterus  a  much  coiled 
canal,  which  while  never  forming  a  rosette  is  usually  somewhat  enlarged  before 
its  opening. 

Sexually  mature  in  the  intestines  of  fishes  and  marine  turtles;  larval  condi- 
tions mostly  unknown. 

Type  genus:  Triaenophorus  Rudolphi. 

TRIAENOPHORUS  Rudolphi  1793 


Vesicaria,  Cysticercus  et 

Taenia  (omn.  part.) 

Auctorum 

Triaenophorus  vel  Tricuspidaria 

Rudolphi 

1793 

Tricuspidaria 

Rudolphi 

1793 

Triaenophorus 

Rudolphi 

1793 

Rhytebninthus  (part.) 

Zeder 

1800 

Rhytis  (part.) 

Zeder 

1803 

Tricuspidaria 

Rudolphi 

1802 

Tricuspidaria 

Rudolphi 

1809 

Triaenophorus 

Rudolphi 

1809 

Tricuspidaria 

Rudolphi 

1810 

Tricuspidaria 

Lamarck 

1816 

Triaenophorus 

Rudolphi 

1819 

Triaenophorus 

Creplin 

1839 

Triaenophonas 

Dujardin 

1845 

Triaenophorus 

Diesing 

1850 

Triaenophorus 

Baird 

1853 

Triaenophorus 

Molin 

1858 

Triaenophorus 

Molin 

1861 

Triaenophorus 

Diesing 

1863 

Triaenophorus 

Olsson 

1867 

Triaenophorus 

Lonnberg 

1889 

Triaenophorus 

Olsson 

1893 

Triaenophorus 

Liihe 

1899 

Triaenophorus 

Liihe 

1899 

Triaenophorus 

Braun 

1900 

Triaenophorus 

Liihe 

1900 

Tricuspidaria 

Stiles  and  Hassall 

1902 

Triaenophorus 

Liihe 

1910 

S2  ILLINOIS  BIOLOGICAL  MONOGRAPHS  [370 

Scolex  armed  with  four  three-pointed  hooks,  never  replaced  by  a  pseudosco- 
lex.  External  segmentation  completely  absent.  Longitudinal  nerves  dorsal 
to  the  cirrus-sac  and  vagina,  close  to  the  lateral  borders.  Testes  between  the 
ner\'e  strands  only,  filling  up  the  whole  medullar\'  parenchyma  so  far  as  this 
is  not  occupied  by  other  organs;  a  testis-free  middle  field  is  quite  as  infrequently 
present  as  a  pronounced  dorsal  layer  of  the  testes.  Coiling  of  the  \'as  deferens 
in  its  proximal  almost  medially  situated  part,  that  portion  passing  distad  to  the 
cirrus-sac  only  very  slightly  coiled.  Vitelline  follicles  form  a  continuous  mantle 
between  the  subcuticula  and  the  longitudinal  musculature,  which  is  broken  only 
at  the  places  where  the  genital  ducts  open.  0\'ary,  approaching  the  lateral  bor- 
der bearing  the  genital  openings,  lies  on  the  ventral  transverse  musculature, 
yet  individual  ovarian  tubules  extend  partly  thruout  the  whole  medulla.  Shell- 
gland  just  as  infrequently  median  as  the  ovary  h'ing  behind  it,  also  usually 
approaching  the  dorsal  surface  somewhat.  First  portion  of  the  uterus  only 
a  weakly  coiled  canal  (uterine  duct)  which  passes  thru  the  proglottis  transverse- 
ly and  leads  into  a  large  single  cavity  (uterus-sac)  which  lies  not  exceptionally 
ahead  of,  but  yet  partly  near  the  ovar}-,  and  usually  not  median  but  away  from 
the  margin  bearing  the  genital  openings.  The  latter  also  applies  naturally  to 
the  uterus-openings  which  breaks  thru  later.    Eggs  thick-shelled,  operculate, 

T\-pe  species:  T.  «odi</o5a  (Pallas  1781)  Rudolphi  1793. 

As  indicated  in  the  above  s\Tionymy  the  name  Triaenophorus  has  absolute 
page  priority  altho  Stiles  and  Hassall  (1902:22)  have  contended  that  Rudolphi 
should  not  have  changed  the  name  of  the  genus  in  1819  from  Tricuspidaria 
to  Triaenaphorus  again,  after  having  used  it  in  connection  with  the  specific 
description  in  1810.  The  change  has  become  so  universally  established  in 
the  literature  that  it  does  not  seem  justifiable  to  revert  to  the  name 
Tricuspidaria  which  is  known  to  only  a  comparatively  small  group  of  zoologists. 

TRIAENOPHORUS  sp.  lar\-. 
[Figs.  12-18] 

Since  all  of  the  material  at  hand  was  larval,  not  even  the  earliest  traces  of 
the  reproductive  rudiments  showing  in  toto  preparations  of  the  largest  speci- 
mens, it  was,  of  course,  impossible  to  determine  the  species  with  certainty. 

Two  types  of  scolices  are  present,  however,  and  these  agree  with  the  de- 
scriptions of  the  organ  given  by  various  authors  for  T.  nodidosns  (Pallas)  and 
by  Olsson  (1893:20)  and  Fuhrmann  (1910:88)  in  parricxilar,  for  T.  rohustus 
Olsson.  It  will  be  seen  also  in  the  table  below  that  these  two  forms  are  foxmd 
respectively  encysted  in  the  liver,  on  the  visceral  organs,  or  in  the  wall  of  the 
stomach,  and  encysted  in  the  muscles  or  free  in  the  intestine  of  the  hosts — 
in  the  latter  case  so  firmly  attached  to  the  wall  as  to  be  deeply  imbedded,  the 
mucosa  forming  a  protruding  collar  around  the  worm — the  only  exception 
being  those  from  the  intestines  of  Esox  masquinongy  and  Stizostedion  vitrenm 
(vide  infra).  Olsson  pointed  out  that  these  two  species  can  be  readily  differ- 
entiated from  each  other  on  account  of  the  situations  in  which  they  undergo 
their  development.    Whereas  the  larvae  of  T.  noduiosus  are  foimd  generally 


371] 


PSEUDOPHYLUDEA  FROM  FISHES—COOPER 


83 


within  cysts  in  the  liver  of  the  intermediate  hosts,  as  recorded  by  a  number  of 
writers,  those  of  T.  rohustus  are  constantly  encysted  in  large  numbers  in  the 
flesh — Olsson  having  found  them  in  Coregonus  albula  and  C.  lavaretus,  Luther 
(1909:58)  in  C.  albula,  and  Fuhrmann  in  the  "brochet"  (?  Esox  lucius). 

The  scolex  of  the  rohustus  type  (Figs.  12  and  13)  is,  as  described  by  Olsson, 
in  the  form  of  a  truncated  rectangular  pyramid,  that  part  immediately  behind 
the  terminal  disc  being  considerably  constricted  and  more  nearly  elliptical 
in  transverse  section.  As  stated  by  Fuhrmann.  "La  limite  posterieure  du 
scolex  de  T.  rohustus  est  nettement  marquee  et  les  deux  bothrias,  I'un  dorsal 
I'autre  ventral,  son  tres  profonds.  ..."  This  delimitation  of  the  scolex  is 
emphasized  by  the  fact  that  immediately  behind  the  posterior  border  of  the 
bothria  the  dorsal  and  ventral  surfaces  of  the  body  of  the  larva  are  distinctly 
concave  as  are  also  the  lateral  surfaces,  quite  diagrammatically,  in  fact,  as 
shown  in  the  figures.  These  concavities  extend  farther  back  for  a  few  milli- 
meters and  then  gradually  flatten  out  and  pass  insensibly  into  the  convexities 
which  together  form  the  elliptical  outline  of  the  cross-section  of  the  middle 
of  the  larva.  And  it  should  be  emphasized  that  this  was  found  to  be  a  con- 
stant feature  of  all  the  material  studied  and  not  simply  .due  to  any  possible 
local  collapsing  during  dehydration.  Altho,  as  shown  in  the  table,  the  measure- 
ments of  the  whole  scolex  are  much  smaller  than  those  given  by  Fuhrmann, 
as  might  be  expected  it  is  chiefly  the  structure  and  size  of  the  trident  of  hooks 
that  leads  the  writer  to  consider  this  type  of  larva  to  belong  to  T.  rohustus. 
Figure  14  of  one  of  these  compares  very  favorably  with  those  shown  in  Olsson's 
figures  31  and  32  and  Fuhrmarm's  figure  2,  while  the  measurements  (see  table) 
quite  agree  with  those  given  by  the  latter.  The  base  of  the  trident  is  com- 
paratively long  or  deep  (in  the  sagittal  direction),  hence  the  specific  name 
according  to  Olsson,  while  not  only  the  full  length  of  the  larger  hooks  but  also 
a  good  deal  of  the  median  ones  project  thru  the  cuticula  as  the  functional  tips. 
In  figure  14,  which  is  from  an  alcoholic  specimen,  these  are  seen  to  be  darker 
than  the  basal  piece.  The  following  measurements  are  given  for  comparison 
with  Fuhrmann's  of  adult  specimens,  which  are  placed  alongside,  the  data  in 
parentheses  being  of  the  opposite  trident  on  the  same  surface  of  the  scolex  in 
question: 


Host 

Esox  lucius 

Leucichthys  artedi 

After  Furmann 

Length 

147.5mm. 

123.0m. 

183.0mm.        47.0mm. 

310-370mm. 

Breadth  (maxi- 

mum) 

1.07 

1.16 

0.98                 1.10 

4.00-4.50 

Length  of  sco- 

lex 

0.98 

0.96 

1.02                 1.12 

1.14-1.50 

Breadth  of 

term.  disc. 

0.77 

0.83 

0.84                0.84 

0.95 

Breadth  of  sco- 

lex poster- 

ly 

1.05 

1.07 

1.30                 1.08 

1.40-1.50 

84 


ILLINOIS  BIOLOGICAL  MONOGRAPHS 


[372 


Host 

Esolucius 

Leucichthes  artedi 

After  Fuhrmann 

Width  of  tri- 

dent 

0.31(0.30)     0.30(0.30) 

0.32            0.28 

0.29-0.32 

Length, 

mediad 

0.25(0.24)     0.23(0.23) 

0.27            0.22 

0.24-0.28 

Length,  exter- 

nally- 

0.18(0.18)     0.16(0.18) 

0.24            0.18 

0.18-0.20 

Measured  in 

Oil  of  wintergreen 

Alcohol 

Olsson  spoke  of  the  larva  of  T.  rohistus  being  provided  with  a  narrower  cyhn- 
drical  "cauda"  as  in  certain  Tetrarhynchus  larvae,  and  gave  the  length  of  one 
as  120nim.,  while  the  anterior  portion  was  approximately  60mm.  long.  Such 
structures  were  seen  posteriorly  in  many  of  the  larger  larvae  at  hand  but  their 
lengths  and  degrees  of  distinction  from  the  fore-body  varied  considerably. 
A  medium  large  one,  in  a  lot  from  Esox  lucius,  for  instance,  had  these  measure- 
ments: Length  of  anterior  portion,  48mm.,  of  cauda  24,  of  scolex  1.16;  width 
of  forebody  0.66,  of  cauda  0.37  (3:1 — Olsson).  The  specimen  from  Leucich- 
thys  artedi  dealt  with  in  the  third  column  of  the  above  table  possessed  a  cauda 
110mm.  in  length,  while  that  treated  in  the  fourth  column  had  no  posterior 
appendage  at  all.  As  for  its  anatomical  structure  this  organ  is  characterized 
by  very  poorly  developed  cuticula  and  musculature,  and  a  ver\'  loose  or  open 
parenchymatous  mesh-work. 

As  may  be  seen  by  reference  to  the  host  record  given  below  the  specimens 
taken  from  Leucichthys  artedi  were  the  only  ones  belonging  to  this  type  of 
larva  which  were  found  encysted.  From  26  specimens  of  the  host  examined 
by  the  writer,  14  cysts,  each  containing  a  single  larva,  were  taken.  Each  fish 
harbored  one  or  two  cysts,  but  one  contained  four.  The  cysts  themselves 
are  from  15  to  45mm.  in  length  and  2  to  3mm.  in  diameter,  and  cyUndrical  in 
shape,  with  bluntly  pointed  ends.  They  are  often  attentuated  at  one  end  to 
such  an  extent  that  at  first  sight  they  appear  to  be  terminated  by  a  mere  thread. 
This  is  found,  however,  on  closer  examination  to  be  hollow  and  to  place  a 
more  distal,  but  som.ewhat  smaller  portion  of  the  cyst  in  communication  with 
the  main  body.  In  situ  these  cysts  are  located  constantly  in  the  myocommata 
of  the  dorsal  musculature  of  the  host,  from  a  short  distance  back  of  the  dorsal 
fin  to  close  behind  the  skull,  and  with*  their  longitudinal  axes  directed  down- 
ward, inward,  and  forward  towards  the  spinal  column,  or,  indeed  as  was  seen 
in  one  case,  actually  towards  the  dorsal  aorta.  Often  they  are  found  doubled 
on  themselves  in  a  V-shaped  manner.  Their  translucent  white  or  somewhat 
opalescent  color  is  due  to  the  contents,  which  besides  the  worm  coiled  on  itself 
several  times  consists  of  a  caseous  substance,  showing  thru  the  thin  wall. 

On  the  other  hand,  the  other  type  of  larva  which  is  considered  by  the 
writer  to  belong  to  T.  nodulosus,  is  characterized  by  a  much  shorter,  narrower 
body,  smaller  at  irregular  intervals  owing  to  differences  of  contraction,  whence 
the  specific  name,  and  by  a  quite  different  scolex  provided  with  the  well- 


373] 


PSEUDOPHYLLIDEA  FROM  FISHES— COOPER 


85 


known  form  of  trident  (Figs.  15  to  16).  While  the  latter  and  the  scolex  as  seen 
in  surficial  view  agree  in  essentials  with  the  descriptions  and  figures  given  by 
various  authors,  e.g.,  Rudolphi  (1810:32,  Tab.  IX,  Figs.  6-11),  Wagener  (1854: 
26,  Tab.  2,  Figs.  17-21),  Olsson  (1893:20,  Figs.  28-32)  and  Fuhrmann  (1910:86, 
Fig.  1),  it  cannot  be  said  of  the  material  studied  that,  as  stated  by  the  last 
writer,  "...  chez  T.  nodulosus  on  ne  pent  voir  aucune  limite  entre  le  scolex 
et  le  cou  du  Bothriocephale.  ..."  For  in  lateral  view  (Fig.  16)  the  bothria 
are  distinctly  separated  from  the  beginning  of  the  body,  which  is,  as  just  men- 
tioned, not  nearly  so  apparent  in  surficial  view.  As  shown  in  figure  15,  the 
middle  hook  of  the  trident  scarcely  protrudes  thru  the  cuticula,  since  it  is  the 
root  for  muscular  attachment.  The  upper  median  hook  (cf.  Wagener)  which 
does  protrude  in  the  adult  is  evidently  not  yet  developed  (Figs.  17  and  18). 
For  a  short  distance  behind  the  scolex  the  body  is  somewhat  rectangular  in 
cross-section,  the  sides  of  the  rectangle  being,  however,  slightly  convex  and 
not  concave  as  in  the  robustus  type,  and  hence  not  so  very  different  from  the 
cross-section  of  the  body  farther  back.  But  the  material  contained  in  the 
lot  from  the  intestine  of  Esox  masquinongy  does  not  strictly  answer  this  de- 
scription since  the  body  just  behind  the  scolex  is  slightly  concave  on  all  sides. 
Otherwise  the  specimens  are  distinctly  of  the  nodulosus  type.  It  should  be 
mentioned,  too,  that  one  of  this  lot  showed  a  very  short  but  distinct  caudal 
piece;  but  this  with  the  general  stout  appearance  of  all  of  them  may  be  account- 
ed for  by  the  possibility  that  they  have  reached  the  intestine  of  one  of  their 
final  hosts  and  continued  their  development.  Likewise  a  few  of  the  specimens 
of  the  lots  from  the  "white  bass"  and  Stizostedion  canadense  were  provided  with 
short  caudal  appendages.  The  smallest  example  of  this  type  and  of  all  the 
material,  for  that  matter,  at  hand  was  that  from  Micropteriis  dolomieu  of  the 
accompanying  table.  Altho  it  is  only  a  little  over  two  and  a  half  millimeters 
in  length,  its  posterior  end  shows  that  a  portion,  perhaps  a  caudal  piece,  has 
been  torn  away.  The  following  table  gives  measurements  of  a  number  of 
specimens  of  the  nodulosus  type,  similar  to  those  given  above  for  the  robustus 
type,  with  Fuhrmann's  data  for  comparison: 


Catostomus 

Esox 

Microplerus 

Host 

commersonii 

masquinongy 

dolomieu 

After  Fuhrmann 

Length 

Piece 

Piece 

Piece      2.68 

120-180mm. 

Breadth  at  middle 

0.61 

0.37 

0.42       0.30 

2.50-4.00 

Length  of  scolex 

0.92 

0.63 

0.55       0.55 

0.95 

Width  term.  disc. 

0.42 

0.35 

0.37       0.31 

0.37-0.47 

Width  of  scolex 

posteriorly 

0.64 

0.37 

0.37       0.26 

0.57-0.60 

Width  of  trident 

0.19 

0.15 

0.15       0.13 

0.125 

Width  of  trident 

medially 

0.14 

0.13 

0.11       0.14 

0.073 

Width  of  trident 

externally 

1.11 

0.09 

0.08       0.10 

0.062 

Measiired  in 

Oil  of  win 

tergreen 

86 


ILLINOIS  BIOLOGICAL  MONOGRAPHS 


[374 


It  will  be  noticed  that  in  spite  of  the  fact  that  all  of  the  measurements  of 
the  tridents  are  larger  than  those  given  by  Fuhrmann,  they  are  considerably 
smaller  than  those  of  the  other  type. 

Finally,  altho  no  specimens  of  either  type  of  larva  so  young  that  the  hooks 
had  not  yet  developed  were  met  with,  those  from  the  intestine  of  Stizostedion 
vitreum  were  provided  with  only  very  small  tridents  of  the  nodulosus  form, 
the  bases  of  which  were  not  yet  well  developed.  The  whole  scolices  were  a 
sort  of  compromise  between  the  two  types  in  shape  but  of  the  nodulosus  tx'pe 
as  regards  size,  as  shown  in  the  following  measurements:  Length,  12mm.; 
width  at  middle,  0.64;  length  of  scolex,  0.87;  width  of  terminal  disc,  0.64;  same 
of  scolex  posteriorly,  0.80;  width  of  trident,  0.14,  length  medially,  0.07,  ex- 
ternally, 0.05.  Altho  these  specimens  would  seem  to  represent  an  intermediate 
stage  between  the  two  types  of  scolex  so  far  as  the  general  shape  is  concerned, 
the  writer  was  inchned  to  consider  them  as  belonging  to  the  nodulosus  type; 
yet  it  must  be  said  that  smaller  scolices,  e.g.,  those  from  M.  dolomieu  in  the 
table,  have  considerably  larger  hooks. 

On  the  whole,  then,  the  bulk  of  the  evidence  given  here  tends  to  show  that 
here  in  America  there  are  probably  two  species,  very  closely  related  to,  if  not 
identical  with,  the  European  T.  nodulosus  and  T,  robustus  which  have  been 
clearly  distinguished  by  Fuhrmann  (1910)  and  also  recognized  by  Liihe  (1910: 
23).  However,  no  adults  have  as  yet  been  reported  for  this  continent,  so  far 
as  the  writer  is  aware. 

The  material  studied  is  here  listed  as  a  host  record  also: 


LOT 

HOST 

LOCATION 

LOCALITY 

COLLECTOK 

Type  robustns: 

36 

Esox  lucius 

Intestine 

Flat  Rock  L. 
Muskoka,  Ont. 

Cooper 

36a,  36b,  36c 

Esox  lucius 

Intestine 

Go-Home  R., 
Muskoka,  Ont. 

Cooper 

161,  163,  183, 

Esox  lucius 

Intestine 

Go-Home  Bay, 

Cooper 

162 

Lota  maculosa 

Intestine 

Off  Giant's  Tomb 
Id.,  Georgian  Bay, 
Lake  Huron 

Cooper 

15.47 

"Lake  Herring" 

?  Intestine 

Lake  Superior 

H.  B.  Ward 

186a,  194b, 

Leucichthys  artedi 

Muscles 

Douglas  Lake, 

G.  R.  LaRue 

195a,  196a, 

Michigan 

197a,  25f,  25g 

331,  333,  336, 

Leucicluhys  artedi 

Muscles 

Douglas  Lake, 

Cooper 

337 

Michigan 

375] 


PSEUDOPHYLLIDEA  FROM  FISHES— COOPER 


87 


Type  nodulosus: 

Host 

Location 

Locality 

Collector 

71 

Perca  flavcscens 

In  liver 

St.  Lawrence  R., 
Iroquois,  Ont. 

Cooper 

151, 188 

Microplerus  dolomieu 

In  viscera 

Go-Home  Bay 

Cooper 

195 

Caloswmus  comtner- 
sonii 

? 

Georgian  Bay 

Cooper 

Eh3b 

Noiropis  delicatus 

? 

Charlevoix,  Mich. 

H.  B.  Ward 

10213 

"White  Bass" 

Liver 

? 

H.  B.  Ward 

N.  S.  28a 

SUzostedion  canadense 

Stomach  wall 

New  Baltimore, 
Michigan 

H.  B.  Ward 

40 

S.  vitreum 

Intestine 

Flat  Rock  L. 

Cooper 

35 

Esox  masquinongy 

Intestine 

Go-Home  R. 

Cooper 

88  ILUNOIS  BIOLOGICAL  MONOGRAPHS  [376 


FISTULICOLA  Liihe  1899 


Taenia  (part.) 

Pallas 

1781 

Bothriocephalus  (part.) 

Rudolphi 

1819 

Bothriocephalus  (part.) 

Leuckart 

1819 

Bothriocephalus  (part.) 

Dujardin 

1845 

Dibothrium  (part.) 

Diesing 

1850 

Dibothrium  (part.) 

Diesing 

1863 

Bothriocephalus  (part.) 

Linstow 

1878 

Bothriocephalus  (part.) 

Carus 

1885 

Bothriocephalus  (part.) 

Matz 

1892 

Bothriotaenia  (part.) 

Ariola 

1896 

Bothriotaema  (part.) 

Riggenbach 

,    1896 

Fistulicola 

Liihe 

1899 

Bothriotaema  (part.) 

Ariola 

1900 

Fistulicola 

Braun 

1900 

Fistulicola 

Liihe 

1902 

Scolex  unarmed,  arrow-shaped  (since  the  posterior  borders  of  the  surficial 
bothria  protrude  comparatively  strongly),  may  be  replaced  by  a  pseudoscolex. 
Neck  absent.  Chain  of  proglottides  very  thick,  so  that  transections  may  be 
nearly  circular.  Segmentation  strongly  expressed,  the  individual  proglottides 
very  short  with  leaf-like,  free  lateral  portions.  Longitudinal  nerves  strongly 
approaching  the  lateral  borders;  individual  testes,  however,  are  also  present 
outside  of  them.  Pronounced  coiling  of  the  vas  deferens  in  its  proximal  por- 
tion; the  distal  part  near  the  cirrus-sac  only  weakly  coiled.  Receptaculum 
seminis  comparatively  small  and  obscure,  but  at  the  same  time  sharply  set  off 
from  the  narrow  terminal  portion  of  the  vagina  (the  spermiduct),  which  in 
contrast  with  the  Ligulinae,  Dibothriocephalinae  and  Cyathocephalinae  is 
comparatively  long.  Ovar>'  and  shell-gland,  near  the  corresponding  parts 
of  the  female  ducts,  are,  in  consequence  of  the  shortness  of  the  proglottides  and 
the  strong  development  of  the  uterus,  forced  away  from  the  position  which  they 
usually  occupy  in  the  Dibothriocephalidae,  or  towards  the  ventral  surface  or 
the  margin  bearing  the  genital  openings.  Vitelline  follicles  extraordinarily 
numerous,  not  confined  to  two  lateral  fields,  but  in  the  form  of  a  ring,  outside 
of  the  longitudinal  muscxilature  in  the  free  lateral  leaf-like  portions  of  the 
proglottides.  Uterus  a  comparatively  wide,  strongly  coiled  canal;  that  portion 
near  its  opening  ver>'  muscular.  The  eggs  pass  thru  their  embryonic  develop- 
ment (at  least  for  the  most  part)  in  the  uterus. 

Type  species:  F.  plicatus  (Rudolphi). 


377] 


PSEU DOPEY LLIDEA  FROM  FISHES— COOPER 


FISTULICOLA  PLICATUS  (Rudolphi  1819) 


89 


1781 

Taenia  haeruca 

Pallas 

1781 

:108 

1790 

Echinorhynchus  xiphiae 

Gmelin 

1790 

:3047 

1803 

Echinorhynchus  xiphiae 

Zeder 

1803 

:162 

1809 

Echinorhynchus  xiphiae 

Rudolphi 

1809 

:308 

1816 

Echinorhynchus  xiphiae 

Lamarck 

1816 

:582 

1819 

Bothriocephalus  plicatus 

Rudolphi 

1819 

:  136,  470 

1819 

Bothriocephalus  truncatus 

Leuckart 

1819 

:37 

1829 

Bothriocephalus  plicatus 

Creplin 

1829 

:87 

1839 

Bothriocephalus  plicatus 

Creplin 

1839 

:297 

1845 

Bothriocephalus  plicatus 

Dujardin 

1845 

:614 

1850 

Dibothrium  plicatum 

Diesiag 

1850 

:591 

1854 

Dibothrium  plicatum 

Wagener 

1854 

:71 

1863 

Dibothrium  plicatum 

Diesing 

1863- 

-.243 

1869 

Bothriocephalus  plicatus 

Cobbold 

1869  ; 

:71 

1871 

Dibothrium  plicatum 

Van  Beneden 

1871  ; 

:36 

1878 

Bothriocephalus  plicatus 

Linstow 

1878  : 

:218 

1885 

Bothriocephalus  plicatus 

Cams 

1885  : 

:120 

1890 

Dibothrium  plicatum 

Linton 

1890  ; 

;746 

1892 

Bothriocephalus  plicatus 

Matz 

1892  ; 

:117 

1896 

Bothriotaenia  plicata 

Ariola 

1896 

1896 

Bothriotaenia  plicata 

Ariola 

1896 

:280 

1896 

Bothriotaenia  plicata 

Riggenbach 

1896 

:223 

1898 

Dibothrium  plicatum 

Linton 

1898 

:430 

1898 

Bothriocephalus  plicatus 

Muehling 

1898  : 

:36 

1899 

Fistulicola  plicatus 

Liihe 

1899  : 

37 

1899 

Fistulicola  plicatus 

Liihe 

1899a 

1900 

Bothriotaenia  plicata 

Ariola 

1900 

:437 

1900 

Fistulicola  plicatus 

Braun 

1900  : 

:1695 

1900 

Fistulicola  plicatus 

Luhe 

1900a 

:  98 

1901 

Dibothrium  plicatum 

Linton 

1901  ; 

:267 

1901 

Dibothrium  plicatum 

Linton 

1901a 

:  412,  448 

• 

1902 

Fistulicola  plicatus 

Liihe 

1902a 

:  321,  324, 

329 

1903 

Bothriotaenia  plicata 

Barbagallo  and 
Drago 

1903  : 

412 

. 

1905 

Fistulicola  plicata 

Spengel 

1905  : 

273 

1914 

Fistulicola  plicatus 

Rudin 

1914  : 

321 

Specific  diagnosis:  With  the  characters  of  the  genus.  Large  cestodes  with 
maximum  length,  breadth  and  thickness  of  250  (about  60  when  contracted), 
20  and  5mm.  respectively.  Scolex  somewhat  orbicular,  2mm.  long,  1.3  wide 
and  1.8  thick;  present  only  in  young  strobilas  which  are  free  in  the  intestine 
of  the  host;  later  it  becomes  modified  as  does  a  considerable  portion  of  the 
anterior  end  of  the  strobila  to  form  a  pseudoscolex  which  is  found  deeply  im- 
bedded in  the  wall  of  the  host's  rectum  or  completely  piercing  it.  Segmenta- 
tion begins  immediately  behind  the  scolex  or  pseudoscolex.  First  and  middle 
segments  very  short  and  broad,  with  prominent  posterior  and  wavy  borders; 
posterior  joints  0.4,  7  and  3mm.  in  length,  breadth  and  thickness  respectively, 
furmel-shaped  with  prominent  posterior  borders  which  occupy  two-thirds 
or  more  of  the  transverse  diameter;  terminal  segments  relatively  much  longer, 
narrower  and  conical  in  shape,  their  posterior  margins  very  thin  and  leaf-like. 


90  ILLINOIS  BIOLOGICAL  MOXOGRAPHS  [378 

Cuticula  10^  in  thickness,  subcuticula  50  to  55/^.  Calcareous  bodies  15 
to  25  by  10  to  15/i  in  dimensions,  mostly  outside  of  the  longitudinal  muscles. 
Latter  not  in  bundles  but  distributed  thruout  the  cortical  parenchyma,  separa- 
ted into  outer  and  inner  groups  only  in  young  proglottides.  Transverse  and 
sagittal  fibres  likewise  diffuse,  former  more  numerous,  however,  just  outside 
of  the  medulla.  Chief  nerve  strand  45^  in  diameter,  situated  far  towards  the 
margin  of  the  strobila  on  each  side,  passing  dorsal  to  the  cirrus-sac  and  vagina. 
Excretor}'^  system  in  the  form  of  a  plexus  of  vessels  ramifying  thruout  the  whole 
of  the  medulla,  of  which  one  just  within  the  ner\'e  on  each  side  is  small  in 
caUber  but  provided  with  thick  muscular  Avails. 

No  genital  cloaca,  but  the  vagina  opens  immediately  behind  the  cimis-sac, 
the  outer  half  of  which  forms  a  protruding  papilla  from  0.4  to  0.6rMn.  in  length 
and  with  a  marked  constriction  at  its  base.  Uterus  opening  about  half-way 
between  the  median  line  and  the  margin  bearing  the  other  genital  apertures, 
and  on  the  free  posterior  portion  of  the  proglottis. 

Testes  polyhedral  in  shape;  closely  arranged,  forming  a  dorsal  layer  con- 
tinuous from  side  to  side  but  discontinuous  from  proglottis  to  proglottis; 
90  to  130, 55  to  75  and  90  to  ISSn,  in  length,  breadth  and  thickness  respectively; 
quite  numerous  outside  of  the  nerve  strands,  at  least  200  to  each  proglottis. 
Vas  deferens  strongly  coiled  and  compact  in  the  median  line,  less  coiled  lateral- 
ly; median  and  distal  portions  lined  with  ciliated  epithelium;  no  special  en- 
largement at  any  point  in  its  course  to  form  a  vesicula  seminalis.  Cirrus-sac 
0.5  to  0.7mm.  in  length  by  0.2  to  0.4  in  maximum  diameter;  outer  half  or  more 
forming  the  pyriform,  protruding  cirrus,  the  cuticula  over  which  is  deeply  cleft. 
This  functional  cirrus  may  be  augmented  in  length  by  the  further  evagination 
of  the  cirrus  proper  from  the  papillar>'  portion  of  the  organ. 

Immediately  within  its  opening  the  vagina  is  surrounded  by  a  sphincter, 
0.2mm.  in  diameter,  which  is  followed  by  a  slight  enlargement  of  the  lumen  to 
a  diameter  of  60/x ;  much  coiled  laterally  but  straighter  medially ;  lOfj.  in  diameter 
at  the  middle  of  its  course;  spermiduct  inconspicuous.  Ovary  irregular  in 
shape,  median  in  position  and  considerably  depressed,  0.7mm.  in  transverse 
diameter  by  0.1  in  thickness,  isthmus  prominent,  ova  from  same  25 fx  in  maxi- 
mum diameter.  Oocapt  25m  in  diameter,  oviduct  40/z.  Vitelline  reservoir 
75m  in  diameter  when  filled  with  vitelline  material.  Vitelline  follicles  irregular 
in  shape,  very  numerous;  discontinuous  from  proglottis  to  proglottis,  but  form 
a  continuous  layer  laterally  and  dorsoventrally  in  the  free  posterior  borders 
of  the  segments.  Shell-gland  inconspicuous.  Uterus  in  graA-id  joints  occu- 
pies almost  the  whole  of  the  medulla;  0.16  to  0.20mm.  in  diameter  at  its  middle; 
the  terminal  portion  quite  muscular,  and  sharply  separated  from  the  duct 
immediately  before  it,  0.2  to  0.3nmi.  in  length  by  0.10  to  0.15  in  diameter; 
opening  irregular  in  shape  and  size. 

Eggs  thick-shelled  (2  to  4/i)  with  dimensions  of  0.09  to  0.10  by  0.05  to 
0.06mm. 

Habitat:  In  the  rectum — less  frequently  in  the  stomach  and  anterior  por- 
tion of  the  intestine — of  the  host. 


379] 


PSEUDOPHYLUDEA  FROM  FISHES— COOPER 


91 


HOST 

LOCALITY 

COLLECTOR 

AUTHORITY 

Xiphias  gladius  (type  host) 

Pisa 

Redi 

Rudolphi 

1809  :  309 

Xiphias  gladius 

Baltic  Sea 

Rudolphi 

Rudolphi 

1819  :471 

Xiphias  gladius 

Ticini 

Spedalieri 

Diesing 

1850  :  591 

Xiphias  gladius 

Kais.-Konig. 

Leuckart 

1819  :  37 

Nat'l  Kab. 

Xiphias  gladius 
Xiphias  gladius 

Dujardin 
Diesing 

1845  :  614 

Grypiiswald 

Rosenthal 

1850  :  591 

Xiphias  gladius 
Xiphias  gladius 

M.  C.  V. 

Diesing 
Cobbold 

1850  :  591 

Lynn,  Norfolk, 

Cobbold 

1869  :  71 

England 

Xiphias  gladius 

Coast  of  Norway 

Olsson 

Beneden 

1871  :  36 

Xiphias  gladius 
Xiphias  gladius 
Xiphias  gladius 

Escaut 

Beneden 

1871  ;  36 

Holland 

Beneden 

1871  :  36 

Firth  of  Forth, 

Beneden 

1871  :  36 

Edinburgh 

Xiphias  gladius 

Nizza 

Wagener 

Carus 

1885  :  120 

Xiphias  gladius 

Martha's  Vine- 
yard, Mass. 

Linton 

Linton 

1890  :  750 

Xiphias  gladius 

Geneva 

Ariola 

Ariola 

1896a  :  121 

Xiphias  gladius 

U.  S.  National 

Linton 

1898  :  430 

Museum 

Xiphias  gladius 

Konigsberg 

Braun 

Muehling 

1898  :  36 

Xiphias  gladius 

Siracusa 

Condorelli 

Ariola 

1900  :  438 

Xiphias  gladius 

Naples 

Ariola 

Ariola 

1900  :  438 

Xiphias  gladius 

Casco  Bay,  Me. 

U.  S.  National 
Museum 

Linton 

1901a  :  448 

Xiphias  gladius 

Woods  Hole, 

Mass. 

Linton 

Linton 

1901a  :  448 

Xiphias  gladius 

Messina,  Italy 

Barbagallo  and 
Drago 

Barbagallo 
and  Drago 

1903  :  412 

Xiphias  gladius 

Messina,  Italy 

Janicki 

Rudin 

1914  :  321 

Xiphias  gladitis 

Woods  Hole, 

H.  B.  Ward 

Cooper  (th 

i  present 

Mass. 

paper) 

"Sunfish"  (Mola  ?) 

Woods  Hole, 

V.  N.  Edwards 

Cooper  (th( 

;  present 

Mass. 

paper) 

This  species  has  been  so  well  described  by  Linton  (1890:746),  Ariola  (1896a) 
and  Liihe  (1899a,  1900a)  that  little  need  be  added.  The  writer  would  like 
to  point  out,  however,  that  as  regards  a  few  details  the  material  studied  did 
not  agree  with  the  descriptions  given  by  these  writers. 

After  referring  to  the  fact  that  the  testes  are  not  arranged  in  two  lateral 
fields  but  form  a  continuous  dorsal  layer  and  the  further  fact  that,  contrary 
to  Ariola's  statement,  they  are  to  be  found  evidently  functioning  in  gravid 
segments,  Liihe  (1899a  :709)  stated  that  "Ihre  Anzahl  ('pochi'  nach  Ariola, 
^zahlreich'  nach  Loennberg)  betragt  ca.  50  pro  Proglottis."  In  the  sections 
made  they  were  found  to  be  about  200  in  number  for  each  proglottis,  and  sepa- 
rated from  tho.se  of  the  segments  ahead  and  behind  by  aggregations  of  trans- 
verse and  sagittal  muscles  which  are,  however,  so  narrow  as  to  give  the  closely 


92  ILLINOIS  BIOLOGICAL  MONOGRAPHS  [380 

crowded  organs  the  appearance  at  first  sight  of  being  continuous  thruout  the 
strobila. 

The  vagina  was  described  by  Liihe  ( 1900a  :68)  as  being  provided  with  no 
cuticular  lining  within  the  enlargement  just  beyond  the  sphincter,  but  in  the 
sections  made  by  the  writer  the  cuticula  could  be  followed  for  about  half  the 
length  of  the  whole  duct.  Peripherally  as  in  the  case  of  that  lining  the  terminal 
enlargements,  it  was  seen  to  be  thrown  into  prominent  longitudinal  folds  which 
in  transections  were  in  many  places  fused  together  so  as  to  divide  the  lumen 
into  several  passages.  Farther  on  these  folds  become  less  pronounced  and 
fused,  while  their  borders  towards  the  center  of  the  lumen  gradually  become 
broken  up  into  pseudociha.  Beyond  the  middle  of  the  course  of  the  duct 
these  pseudociha  seem  to  pass  insensibly  into  the  cilia  of  the  proximal  region, 
while  the  cuticula  is  Hkewise  strictly  continuous  with  the  nucleated  epithehum, 
there  being  no  distinct  region,  let  alone  line  of  demarcation  in  either  case.  It 
would  appear,  then,  that  what  are  apparently  true  cilia  in  the  proximal  portion 
of  the  duct  are  merely  modified  cuticular  pseudociha;  or  from  the  standpoint 
of  development  that  the  latter,  as  well  as  the  more  peripheral  ridges,  are 
formed  by  the  gradual  fusion  of  the  former  from  within  outwards.  But  since 
this  view  needs  considerable  ontogenetic  evidence  for  its  support,  it  must  re- 
main for  the  present,  at  least,  a  mere  suggestion  of  possibiHty. 

Otherwise  the  material  studied,  which  was  quite  fragm^entary,  corresponded 
with  the  descriptions  given  by  the  various  authors  of  the  species  found  on  the 
European  side  of  the  Atlantic  Ocean,  as  was  brought  out  by  Linton  (1890) 
for  the  general  features.  It  consisted  of  No.  13.46  of  the  Collection  of  the 
University  of  Illinois  from  the  stomach  wall  of  Xiphias  gladius,  and  one  speci- 
men taken  by  Mr.  V.  N.  Edwards  from  a  "Simfish"  (?  Mola  mola)  at  the 
Woods  Hole  Laboratory  of  the  U.  S.  Bureau  of  Fisheries. 


381]  PSEUDOPHYLLIDEA  FROM  FISHES— COOPER  93 


PTYCHOBOTHRIIDAE  Liihe  1902 

Scolex  unarmed,  with  two  separate  and  more  or  less  strongly  developed 
bothria,  or  exceptionally  replaced  by  a  pseudoscolex.  Neck  absent.  External 
segmentation  never  absent,  but  frequently  incomplete  or  obliterated  thru 
secondary  foldings.  Genital  organs  numerous,  but  only  single  in  each  proglot- 
tis. Both  surfaces  of  the  chain  of  proglottides,  apart  from  the  genital  openings 
similar.  Cirrus  unarmed,  with  cleft  cuticula.  Opening  of  cirrus  and  vagina 
behind  the  uterus  opening,  surficial  or  marginal,  in  the  first  case  on  the  opposite 
surface  to  the  uterus-opening  and  almost  median.  No  muscular  bulb  at  the 
inner  end  of  the  cirrus-sac.  Receptaculum  seminis,  when  present,  has  the 
form  of  a  small  blind  sac  situated  at  the  inner  end  of  the  vagina.  Ovary  and 
shell-gland  median.  Testes  in  two  lateral  fields.  Uterus  never  taking  the 
rosette  shape,  but  usually  forming  a  capacious  undivided  uterus-sac.  Eggs 
thin-shelled,  without  opercula;  embryonic  development  in  the  uterus,  and  in 
consequence  of  exhaustive  production  of  eggs  (but  dependent  on  the  time  of 
year  in  the  case  of  many  species)  all  the  eggs  of  the  whole  tapeworm  are  at  the 
same  stage  of  development. 

Sexually  mature  in  the  intestine  of  fishes;  larval  condition  imknown. 

In  his  first  diagnosis  of  the  family  Liihe  ( 1902a :326)  emphasized  the  similar- 
ity of  both  surfaces  of  the  strobila  (in  contradistinction  to  conditions  in  the 
Acanthophallidae),  the  unarmed  cirrus  with  cleft  cuticula,  the  peculiar  cecal 
receptaculum  seminis  and  the  absence  of  opercula  in  the  eggs,  but  described 
the  uterus  as  follows:  "Uterus  nie  die  sogenannte  Rosettenform  annehmend, 
wohl  aber  in  der  Regel  eine  geraumige  Uterushohle  bildend,  welche  die  iibrigen 
Genitalorgane,  ohne  dass  freiUch  deren  Riickbildimg  eintritt,  buchstablich  an 
die  Wand  drangen  kann,  indem  die  ganze  Proglottis  in  reifen  Proglottiden  viel- 
fach  als  ein  einziger  sackformiger  Eibehalter  mit  verhaltnismassig  sehr  diinnen 
Wandungen  erscheint. "  The  uterus  of  Haplobothrium  answers  this  descrip- 
tion in  that  it  is  divided  into  a  uterus -sac  and  uterine  duct;  but  the  remaining 
reproductive  organs  are  distinctly  diphyllobothriidian  in  their  nature.  Con- 
sequently, in  order  to  differentiate  more  clearly  the  two  famiHes,  Ptychoboth- 
riidae  and  Diphyllobothriidae,  and  especially  since  the  genus  Haplobothrium 
presents  difficulties  in  this  connection,  it  is  necessary  to  know  the  developmen- 
tal relationships  between  the  uterine  duct  and  the  uterus-sac  in  those  genera 
in  which  they  appear.  Up  to  the  present  no  adequate  descriptions  of  the 
latter  have  been  pubhshed,  so  that  here  will  be  given  the  observations  on  the 
development  of  the  uterus  to  which  reference  was  made  above  (p.  16),  where 
the  conditions  in  Haplobothrium  and  Marsipometra  were  discussed. 

In  Bothriocephalus  scorpii  the  lumen  of  the  uterus-sac  appears  suddenly 
and  with  a  diameter  of  90/x,  the  rudiment  ahead  showing  as  yet  no  signs  of 
forming  a  cavity.  This  enlargement  is  situated  at  first,  however,  in  the  cortical 
parenchyma  and  among  the  longitudinal  muscles,  only  the  inner  tip  of  the 


94  ILLINOIS  BIOLOGICAL  MONOGRAPHS  [382 

structure  in  transections  going  into  the  medulla.    Just  within  the  inner  trans- 
verse muscles  this  inner  portion  of  the  sac  is  joined  by  the  uterine  duct  which 
with  a  diameter  of  30m  elsewhere  is  here  only  8/i  in  diameter.     Furthermore,  in 
the  genital  rudiment  of  the  next  proglottis  ahead  there  is  a  distinct  demarca- 
tion between  the  aggregagion  of  nuclei  that  will  form  the  sac  and  the  axial 
rudiment  of  the  uterine  duct.    The  same  separation  of  sac  and  duct  with  the 
narrowing  of  the  latter  just  before  entering  the  former  is  present  in  the  follow- 
ing segments  even  where  the  first  eggs  are  to  be  seen  in  the  lumen.    Thus  the 
eggs  must  have  passed  this  narrowed  region  which  is  a  great  deal  smaller  than 
their  diameters.    Still  farther  back  where  the  lumen  is  about  165^  in  diameter 
there  can  be  seen  not  only  the  situation  of  the  sac  in  the  cortex  and  among  the 
longitudinal  muscles,  projecting  as  yet  only  a  short  distance  into  the  medulla — 
altho  here  the  bundles  of  muscles  are  deflected  peripherally — but  also  the 
separation  of  the  two  parts  by  a  narrow  neck  only  10/u  in  diameter.    B.  aispido 
tus  shows  the  same  distinct  separation  of  the  uterine  duct  and  uterus-sac  in  the 
proglottides  where  there  are  already  a  few  eggs  in  the  latter.    In  Clesiobothrium 
crassiceps  conditions  were  found  to  be  quite  the  same.    WTien  the  lumen  of  the 
sac  attains  dimensions  of  about  60  by  35/i  and  is  lined  with  an  epithelium  which 
takes  the  counterstain  more  like  a  cuticula  but  shows  nuclei  on  its  surface 
towards  the  lumen,  the  uterine  duct  opens  into  it  with  a  distinct  reduction  in 
diameter.    The  epithelia  of  the  two  are,  however,  quite  similar  and  continuous, 
the  nuclei  being  located  in  a  similar  manner  in  both.    Proglottides  ahead  show 
that  the  sac  is  formed  by  an  enlargement  of  the  end  of  the  duct,  which  takes 
place  first  in  that  region  passing  thru  the  cortex  quite  as  in  Bothriocephalus. 
Thus  it  is  seen  that  the  uterus  sac  of  this  family  is  quite  different  from  the 
functional  enlargement  of  the  uterus  of  the  Diphyllobothriidae,  with  the 
exception  of  that  of  Haplobothriiun,  since  at  all  stages  in  its  development  it  is 
sharply  separated  from  the  uterine  duct.    But  as  it  was  not  so  much  this  exact 
separation  of  the  two  portions  as  the  constant  presence  of  an  "  Uterushohle  " 
in  this  family  and  its  absence  in  the  other,  where  the  "  Rosettenform  "  is  more 
common,  that  was  emphasized  by  Liihe,  and  since  the  structure  in  Haplo- 
bothriiun is  distinctly  ptychobothriidian  in  character,  the  functional  enlarge- 
ment of  the  uterus  cannot  now  be  considered  to  be  of  such  systematic  unpor- 
tance  as  was  formerly  believed, 

PTYCHOBOTHRIINAE  Luhe  1899 

Scolex  with  two  surficial  sucking  grooves,  which  may  be  modified  by  con- 
siderable growth  together  of  their  free  edges.  Genital  openings  surficial,  those 
of  the  cirrus  and  vagina  dorsal,  that  of  the  uterus  ventral  and  ahead  of  the  other 
two.  Vas  deferens  strongly  coiled,  dorsal.  Ovary  ventral;  shell-gland  dorsal. 
Vitelline  follicles  usually  in  two  lateral  fields  in  the  cortical  or  medullary 
parenchyma.  Testes  completely  filling  the  medulla,  mostly  marginal  to  the 
longitudinal  nerves  which  are  well  towards  the  median  line. 

Occurrence:  Exclusively  in  fishes. 

Type  genus:  Bothriocephalus  (Rud.)  Liihe. 


383] 


PSEUDOPHYLLIDEA  FROM  FISHES— COOPER 


95 


The  above  diagnosis  lacks  the  words  "seldom  armed"  after  "scolex" 
which  appear  in  Luhe's  latest  (1910:24)  characterization  not  only  of  this 
subfamily  but  of  the  family,  because  they  do  not  appear  in  his  earlier  papers, 
(1899:41  and  1902a:336,  respectively)  nor  does  there  seem  to  the  writer  to  be 
any  occasion  for  their  use. 


BOTHRIOCEPHALUS  Rud.  1808,  e.  p.  Liihe  1899,  e.  p. 


Taenia  (part.) 

Auctorum 

Rhytelminthus  (part.) 

Zeder 

1800 

Alyselminthus  (part.) 

Zeder 

1800 

Rhytis  (part.) 

Zeder 

1803 

Bothriocephalus  (part.) 

Rudolphi 

1809 

Bothriocephalus  (part.) 

.Rudolphi 

1819 

Dibothrius  (part.) 

Rudolphi 

1819 

Bothriocephalus  (part.) 

Leuckart 

1819 

Bothriocephalus  (part.) 

Dujardin 

1845 

Dibothrium  (part.) 

Diesung 

1850 

Bothriocephalus  (part.) 

Baird 

1853 

Dibothriiun  (part.) 

Molin 

1861 

Dibothrium  (part.) 

Diesing 

1863 

Bothriocephalus  (part.) 

Cams 

1885 

Bothriocephalus  (part.) 

Matz 

1892 

Bothriocephalus  (part.) 

Ariola 

1896 

Bothriocephalus  s.  str. 

Liihe 

1899 

Bothriocephalus  (part.) 

Ariola 

1900 

Bothriocephalus  s.  str. 

Braun 

1900 

Bothriocephalus  s.  str. 

Liihe 

1910 

Scolex  elongated,  with  two  only  weakly  developed  sucking  grooves.  Ex- 
ternal segmentation  well  developed;  between  two  consecutive  genital  segments 
there  is  always  present  a  saw-tooth  notching  of  the  lateral  border,  yet  a  corres- 
ponding transverse  furrow  on  both  surfaces  is  sometimes  lacking.  Vitelline 
follicles  in  the  cortical  parenchyma,  continuous  from  proglottis  to  proglottis, 
as  are  the  testes.  Receptaculum  seminis  absent.  Beginning  of  the  uterus 
a  winding  canal  (uterine  duct)  which  opens  into  a  large  nearly  spherical  cavity 
(uterus-sac  or  uterus  s.  str.).  Uterus  opening  approximately  median,  as  is 
the  dorsal  genital  opening. 

Type  species:  Bothriocephalus  scorpii  (Miiller  1776) 


96 


ILLINOIS  BIOLOGICAL  MONOGRAPHS 


[384 


BOTHRIOCEPHALUS  SCORPII  (MliUer  1776) 
[Figs.  21,  22,  55-57,  59-61,  71,  84,  95,  105] 


1722  Vermis  multimembris  rhombi 

1776  Taenia  scorpii 

1780  Taenia  scorpii 

1780  Taenia  scorpii  (part.) 

1786  Taenia  scorpii 

1788  Taenia  scorpii 

1788  Taenia  scorpii 

1790  Taenia  scorpii 

1799  Taenia  scorpii 

1800  Alyselminthus  bipunctatus 
1802  Taenia  punctata 

1802  Taenia  scorpii 

1803  Rhytis  bipunctata 

1810  Bothriocephalus  punctatus 

1819  Bothriocephalus  punctatus 

1819  Bothriocephalus  punctatus 

1844  Bothriocephalus  punctatus 

1845  Bothriocephalus  punctatus 
1850  Bothriocephalus  punctatus 
1850  Dibothrium  punctatum 
1853  Bothriocephalus  punctatus 

1855  Dibothrium  punctatum 

1856  Dibothrium  punctatum 
1858  BothriocepJtalus  punctatus 
1858  Dibothrium  punctatum 
1861  Dibothrium  punctatum 
1863  Dibothrium  punctatum 
1867  BothriocepJtalus  punctatus 
1878  Bothriocephalus  punctatus 
1885  Bothriocephalus  punctatus 

1889  Bothriocephalus  punctatus  forma  bubalidis 

1890  Dibothrium  punctatum 

1891  BothriocepJtalus  punctatus 

1892  Bothriocephalus  punctatus 

1893  Bothriocephalus  punctatus  forma  motellae 
1893  Bothriocephalus  punctatus 

1898  Dibothrium  punctatum 

1899  Bothriocephalus  bipunctatus 

1900  Bothriocephalus  punctatus 
1900  Bothriocephalus  bipunctatus 
1902  BothriocepJtalus  bipunctatus 

1902  BothriocepJtalus  punctatus  forma  puncta- 
tus vel  typica 

1902  Bothriocephalus  punctatus  forma  rhombi 

1902  Bothriocephalus  punctatus  forma  cotti- 
quadricornis  [mihi] 

1910  Bothriocephalus  bipunctatus 

1917  BothriocepJtalus  scorpii 


Leeuwenhoek 

Miiller 

Miiller 

Fabricius 

Batsch 

Miiller 

Schrank 

Gmelin 

Ratke 

Zeder 

Rudolphi 

Bosc 

Zeder 

Rudolphi 

Rudolphi 

Leuckart 

Bellingham 

Dujardin 

van  Beneden 

Diesing 

Baird 

Leidy 

Leidy 

Cobbold 

Molin 

Molin 

Diesing 

Olsson 

Linstow 

Carus 

Loennberg 

Linton 

Loennberg 

Matz 

Loennberg 

Olsson 

Linton 

Liihe 

Ariola 

Braun 

Fuhrmann 

Schneider 

Schneider 
Schneider 

Liihe 
Cooper 


1722  : 
1776: 
1780  : 
1780  : 
1786  : 
1788  : 
1788  : 
1790  : 

1799  : 

1800  : 
1802  : 

1802  : 

1803  : 
1810  : 
1819  : 
1819  : 

1844  : 

1845  : 
1850  : 
1850  : 
1853  : 

1855  : 

1856  : 
1858  : 
1858  : 
1861  : 
1863  : 
1867  : 
1878  : 
1885  : 

1889  : 

1890  : 

1891  : 

1892  : 

1893  : 
1893  : 

1898  : 

1899  : 

1900  : 
1900  : 
1902  : 
1902a 


402 

219 

179 

319 

235 

5-6 

48 

3078 

68 

236 

109-110 

307 

296 

50 

138 

40 

254 

617 

160 

593 

89 

444 

46 

157 

134 

235 

240 

14,55 

237 

120 

32 

731 

51 

105 

13 

16 

430 

43 

394  ■ 

1691 

44^ 

:  14 


1902a  :  15 
1903  :  75 

1910  :  25 
1917  :  37 


Specific  diagnosis:  With  the  characters  of  the  genus.    Large  cestodes, 
up  to  950mm.  long  by  6mm.  wide.     Scolex,  large,  elongate,  with  prominent 


385] 


PSEUDOPHYLLIDEA  FROM  FISHES— COOPER 


97 


terminal  disc,  widest  anteriorly;  length  1.0  to  3.5mm.,  breadth  0.3  to  0.5. 
Bothria  long  and  narrow,  shallow  posteriorly.  First  segments  subcimeate 
with  weakly  prominent  posterior  borders,  longer  than  broad.  Middle  and 
posterior  segments  much  depressed,  former  very  short  and  broad,  latter  rela- 
tively less  so  and  grouped  in  twos  or  threes;  lateral  borders  crenulate.  Ripe 
proglottides  2  to  4mm.  wide  by  0.2  by  0.8  long.  Strobila  usually  incomplete 
posteriorly. 

Cuticula  Sjx  in  thickness.  Calcareous  bodies  13/i  in  diameter.  Inner 
longitudinal  muscles  in  fascicles.    Six  chief  longitudinal  excretory  vessels. 

Opening  of  the  genital  cloaca  at  the  bottom  of  a  dorsal  median  longitudinal 
depression  running  thruout  mature  segments,  on  a  low  papilla  in  each  proglot- 
tis and  half-way  between  the  anterior  and  posterior  borders.  Vaginal  opening 
immediately  behind  that  of  cirrus.    Distinct  ductus  hermaphroditicus  present. 

Testes  subspherical,  35  to  70/x  in  diameter  and  30  to  60  in  each  segment. 
Vas  deferens  a  compact  mass  lateral  to  cirrus-sac  and  opposite  the  uterine 
tube,  0.18  by  0.10mm.  Cirrus-sac  at  right  angles  to  dorsal  surface,  115  by 
120  by  75  to  80/i,  extending  only  a  short  distance  into  the  medulla;  thick  layer 
of  nuclei  within  its  wall.    Cirrus  proper,  not  protruded,  65  by  15/i. 

Ovary  compact,  tubulolobular,  0.33mm.  wide  by  0.15  long  where  uterus- 
sac  is  not  greatly  distended.  Isthmus  only  ventral.  Oocapt  35/i  in  diameter. 
Vitelline  follicles  in  two  lateral  weakly  united  fields  on  each  surface,  350  to 
540  in  number,  35  to  55ai  in  diameter;  vitelhne  reservoir  small.  Shell-gland 
large,  115iu  wide  by  85/x  deep,  median,  close  behind  cirrus-sac.  Uterine  duct 
voluminous  on  both  sides  of  the  median  line,  closely  applied  to  ovary  behind. 
Uterus-sac  spherical  to  flattened  anteroposteriorly,  occupies  one-sixth  of 
transverse  diameter  of  proglottis,  alternating  irregularly  from  side  to  side,  or 
often  quite  median.  Opening  in  middle  of  sac,  ventral  and  well  forward, 
formed  by  the  rupture  of  a  distinct  membrane. 

Eggs,  66  to  80)Lt  in  length  by  43  to  45/1  in  diameter,  without  opercula,  form- 
ing dark  brown  maculations  in  ripe  proglottides  as  they  show  thru  the  walls 
of  the  uterus-sacs. 

Habitat:  In  the  intestine  of  the  host. 


HOST 


COLLECTOR 


AUTHORITY 


Cottus  scorpius  (type  host) 
Cottus  scorpius 
Cottus  scorpius 
Cottus  scorpius 

Cottus  scorpius 
Cottus  scorpius 


Cottus  scorpius 
Cottus  scorpius 


Denmark 
Gryphswald 
Ireland 
"Oresund  e 
Berg,"  Sweden 
Norway 
Grafvema  and 
Naset,  Sea  of 
Bahusia 
Arctic  Ocean 
Gulf  of  Finland 


MuUer 
Rudolphi 
Bellingham 
Olsson 

Loennberg 


Olsson 
Schneider 


Muller         1788  :  6 
Rudolphi     1819  :  139 
BeUingham  1844  :  254 
Olsson  1867  :  55 

Loenberg     1890  :  22 


Olsson         1893  :  16 
Linstow       1901  :  281 
Schneider     1902  :  15 


98 


ILLINOIS  BIOLOGICAL  MONOGRAPHS 


[386 


HOST 

LOCALITY 

COLLECTOR 

AUTHORITY 

Cottus  scorpius 

Murman-Kiiste 

Coll.  Zool.  Mus. 
K.  Akad.  Wiss., 
Petrograd 

Linstow 

1903  :  19 

Coitus  scorpius 

White  Sea 

Danilevskij 

Linstow 

1903  :  49 

Cottus  scorpius 

North  Sea 

NicoU 

NicoU 

1907  :  70 

Cottus  scorpius 

Firth  of  Clyde, 
Millport,  Scotland 

NicoU 

NicoU 

1910  :  355 

Cottus  hubalis 

England 

Cobbold 

Cobbold 

1858  :  157 

Cottus  bubdis 

Norway 

Loennberg 

Loennberg 

1890  :  22 

Cottus  bubdis 

Sweden 

Loennberg 

Loennberg 

1891  :  51 

Cottus  bubdis 

Grafvema  and 
Naset 

Olsson 

Olsson 

1893  :  16 

Cottus  bubdis 

North  Sea 

NicoU 

NicoU 

1907  :  71 

Cottus  quadricornis 

Gulf  of  Finland 

Schneider 

Schneider 

1903  :  75 

Pleuronectes  boscius 

Naples 

Rudolphi 

Rudolphi 

1819  :  139 

Pleuronectes  flesus 

"Oresund  e  Berg" 

Olsson 

Ariola 

1900  :  396 

Pleuronectes  tnaximus 

Denmark 

Miiller 

MuUer 

1788  : 6 

Pleuronectes  tnaximus 

Gryphswald 

Rudolphi 

Rudolphi 

1819  :  139 

Pleuronectes  maxitnus 

Ireland 

Bellingham 

Bellingham  1844  :  254 

Pleuronectes  maxitnus 

Langrunne, 
Rennes 

Dujardin 

Dujardin 

1845  :  618 

Pleuronectes  rhombus 

Naples 

Rudolphi 

Rudolphi 

1819  :  139 

Pleuronectes  rhombus 

Ireland 

Drummond 

BeUingham  1844  :  254 

Pleuronectes  solea 

Kais.-Konig. 

Leuckart 

1819  •  40 

Nat'l  Kab. 

*'-'■*■-'     •    "TV/ 

Torpedo  ocellata 

Naples 

Rudolphi 

Rudolphi 

1819  :  139 

Torpedo  oculaia 
Gadus  aeglifinus 

Volz 

Volz 

1900  :  55 

Arctic  Ocean 

Linstow 

1901  :  281 

Cadus  minutus 

Naples 

Rudolphi 

Rudolphi 

1819  :  139 

Arnoglossus  boscii 

Naples 

Rudolphi 

Ariola 

1900  :  396 

Amoglossus  pegosa 

Ariminus 

Rudolphi 

Rudolphi 

1819  :  139 

Arnoglossus  solea 
Trigla  adriatica 

Mus.  Vienna 

Rudolphi 

1819  :  139 

Hafnia 

Eschricht 

Diesmg 

1850  :  594 

Trigla  lineata 

Ireland 

Drummond 

Diesing 

1850  :  594 

Psetta  maxima 

England 

Siebold  CoU., 
Brit.  Mus. 

Baird 

1853  :  89 

Platessa  plana 

Pennsylvania 

Leidy 

Leidy 

1855  :  444 

Platessa  flesus 
Platessa  passer 
Rhombus  maximus 

Germany 
Trieste 

Liihe 

1910  :  25 

Stossich 

1898  :  116 

Italy 

Molin 

Molin 

1858  :  134 

Rhombus  maximus 

Patavia 

Molin 

Molin 

1861  :  235 

Rhombus  maximus 

"  Oresimd  e  Berg  " 

Olsson 

Olsson 

1867  :  55 

Rhombus  maximus 

Trieste 

Stossich 

Cams 

1885  :  120 

Rhombus  maximus 

Venice 

Ninni 

Stossich 

1890  : 7 

Rhombus  maximus 

Wamemiinde 

Matz 

1892  :  105 

Rhombus  maximus 

Rossitten,  Cranz, 

Muehling 

1898  :  36 

Memel 

Rhombus  maximus 

Trieste 

Stossich 

1898  :  116 

Rhombus  maximus 

Geneva 

Parona  and 
Ariola 

Ariola 

1900  :  395 

Rhombus  maximus 

Trieste 

Stossich 

Stossich 

1901  :  97 

387) 


PSEUDOPHYLLIDEA  FROM  FISHES— COOPER 


99 


HOST 

LOACLITY 

COLLECTOR 

AUTHORITY 

Rhombus  maximus 

Gulf  of  Finland 

Schneider 

Schneider 

1902  :  15 

Rhombus  maximus 

North  Sea 

NicoU 

NicoU 

1907  :  72 

Rhombus  barbue 

Volz 
Olsson 

Volz 
Olsson 

1900  :  55 

Rhombus  laevis 

"OresundeBerg" 

1867  :  55 

Rhombus  laevis 

Grafvema  and 
Naset 

Olsson 

Olsson 

1893  :  16 

Rhombus  maeoticus 

Odessa 

Nordmann 

Linstow 

1901  :  281 

Lophopsetta  maculata 

Martha's  Vine- 
yard, Mass. 

Linton 

Linton 

1890  :  732 

Bothus  maculatus 

Woods  Hole 

Linton 

Linton 

1898  :  430 

Hemitripterus  americana 

U.  S.  Nat.  Mus. 
U.  S.  Nat.  Mus. 

Linton 
Linton 

1898  :  430 

Hcmiiripterus  americana 

Casco  Bay, 

1898  :  430 

Maine 

Linton 

1898  :  430 

Hemitripterus  americana 

Woods  Hole 

U.  S.  Nat.  Mus. 

Limanda  ferruginea 

Block  Id. 

U.  S.  Fish  Com. 

Linton 

1898  :  430 

Limanda  ferruginea 

Woods  Hole 

Linton 

Linton 

1901  :  485 

Labrus  maculatus 

"Oresund  e  Berg" 

Olsson     ' 

Ariola 

1900  :  396 

Motella  mustela 

Mus. 
Vienna 

Ariola 

1900  :  396 

Mullus  barbatus 

Geneva 

Parona 

Ariola 

1900  :  396 

Solea  monochii 

Mus. 
Vienna 

Ariola 

1900  :  396 

Acipenser  ruthenus 

Volz 
Volz 
Linton 

Volz 
Volz 
Linton 

1900  :  55 

Scorpaena  porcus 

1900  :  55 

Paralichthys  oblongus 

Woods  Hole 

1901  :  484 

Lota  vulgaris 

Dvina-Fluss 

Danilevskij 

Linstow 

1903  :  19 

Raja  clavata 

Black  Sea 

Pilat 

Pilat 

1906  :  191 

Anguilla  vulgaris 

River  Dee, 
Scotland 

Scott 

Scott 

1909  :79 

Decapterus  punctatus 

Woods  Hole 

Sumner, 

1913  :  586 

Region 

Osburn 
and  Cole 

Hippoglossus  hippoglossus 

Woods  Hole 
Region 

Sumner, 
Osburn 

1913  :  586 

and  Cole 

Myoxocephalus  aeneus 

Woods  Hole 
Region 

Sumner, 
Osburn 

1913  :  586 

and  Cole 

Myoxocephalus  octodecim- 

Woods  Hole 
Region 

Sumner, 
Osburn 

1913  :  586 

spinosus 

and  Cole 

Palinurichthys  perciformis 

Woods  Hole 
Region 

Siunner, 
Osburn 

1913  :  586 

and  Cole 

Paralichthys  dentatus 

Woods  Hole 
Region 

Sumner, 
Osburn 

1913  :  586 

and  Cole 

Pseudopleuronectes  ameri- 

Woods  Hole 
Region 

Sumner, 
Osburn 

1913  :  586 

canus 

and  Cole 

100 


ILLINOIS  BIOLOGICAL  MONOGRAPHS 


[388 


HOST 

LOCALITY 

COLLECTOR 

AUTHORITY 

Scomber  scomber 

Woods  Hole 
Region 

Sumner,       1913  :  586 

Osbum  and  Cole   " 

Trackurops  crumenophthal- 
mus 

Woods 

Sumner,       1913  :  586 

Region 

Osbum 

and  Cole 

Urophycis  chuss 

Woods  Hole 
Region 

Sunmer,       1913  :  586 

Osbum 

and  Cole 

Hemitripterus  americanus 

Passamaquoddy 

A.  R.  Cooper 

Cooper  (the  present 

Bay,  New  Bruns- 

paper) 

wick 

Eemitripterus  americanus 

Brandy  Cove, 

A.  R.  Cooper 

CooF>er  (the  present 

St.  Croix  R., 

paper) 

New  Brunswick 

Hemitripterus  americanus 

Woods  Hole 

V.  N.  Edwards 

Cooper  (the  present 
paper) 

?  Myoxocephalus  aeneus 

Woods  Hole 

V.  N.  Edwards 

Cooper  (the  present 
paper) 

?  Myoxocephalus  groelandi- 

Woods  Hole 

V.  N.  Edwards 

Cooper  (the  present 

cus 

paper) 

Most  of  the  specimens  studied  ranged  in  length  from  50  to  240mm.,  but 
none  of  them  were  considered  to  be  complete  posteriorly.  The  smallest 
measured  28inm.  in  length  and  the  largest  677mm.  The  scolex  assumes  a 
variety  of  forms  in  preserved  material,  but  agrees  in  general  with  the  descriptions 
of  that  of  B.  scorpii  given  by  all  the  authors  from  the  time  of  Rudolphi  (1810: 
51).  Its  commonest  shape  is  shown  in  figures  21  and  22  where  it  is  seen  to 
be  quite  elongated,  somewhat  broader  and  truncated  anteriorly  and  narrow 
posteriorly.  The  anterior  portion  is  in  reality  in  the  form  of  a  low  pyramid, 
comparable  internally  as  well  as  externally  with  the  terminal  disc  of  the  Tri- 
aenophorinae.  Its  base  is  deeply  indented  dorsoventrally,  that  is  opposite 
the  bothria,  but  rounded  laterally.  The  whole  scolex  is  broadest  at  about  its 
middle  and  narrowest  at  its  posterior  end.  A  portion  of  the  latter  is  here  con- 
sidered to  be  the  beginnings  of  the  first  segment  on  account  of  its  being  con- 
stantly set  off  from  the  rest  of  the  scolex  ahead  by  a  more  or  less  definite  groove. 
The  bothrivmi  is  in  the  form  of  an  elongated  V,  being  ordinarily  widest  and 
deepest  just  behind  the  terminal  disc  and  much  narrower  and  shallower  pos- 
teriorly where  it  is  not  bounded  by  a  definite  wall  but  spreads  out  on  the  base 
of  the  scolex.  In  many  specimens,  however,  the  scolex  is  so  contracted  and 
the  walls  of  the  bothrium  so  protruded  that  the  latter  shows  its  greatest  depth 
at  the  middle  of  the  scolex.  In  lateral  view  (Fig.  22)  the  scolex  is  more  nearly 
o\'al  in  outline  since  it  is  a  little  wider  towards  the  base.  From  this  fact  it  is 
conceivable  that  MiiUer's  (1788, Fig.  7)  showing  a  more  "orbicular"  scolex 
in  B.  scorpii  in  lateral  view  may  be  explained  by  supposing  that  he  was  dealing 
with  a  much  contracted  specimen,  altho  in  justice  to  the  other  side  of  the 
question,  it  must  be  said  that  the  first  segments  in  his  figure  are  by  no  means 
contracted.    It  will  be  noticed  that  the  figures  of  the  scolex  given  here  agree 


389]  PSEUDOPHYLLIDEA  FROM  FISHES— COOPER  101 

very  closely  with  that  of  Scott  (1909,  Fig.  3,  PL  V).  However,  from  the  fact 
that  he  records  B.  scorpii  as  having  been  found  in  Anguilla  vulgaris,  it  is  quite 
possible  that  he  had  in  reality  B.  claviceps  (Goeze)  which  has  been  found  only 
in  eels  up  to  the  present,  so  far  as  the  writer  is  aware. 

Segmentation  begins  immediately  behind  the  scolex,  so  that  there  is  no 
true  neck.  The  base  of  the  scolex,  nevertheless,  has  the  appearance  of  a  very 
short  neck  region  from  which  the  foremost  segments  are  cut  off  as  soon  as  they 
form.  Such  in  fact  is  considered  to  be  the  case.  The  anterior  part  of  the 
strobila  on  the  other  hand  serves  the  purpose  of  a  neck  in  that  it  shows  a  divi- 
sion into  subsegments  in  a  manner  to  be  presently  described.  As  regards  the 
habit  of  the  whole  strobila  and  the  general  shape  of  the  segments,  Rudolphi's 
(1810:51)  description  of  the  species  is  so  appUcable  to  this  form  that  it  is 
given  verbatim: 

"Co//mw  nullum.  Corpus  planum,  margine  crenato.  .<4r/JcM/i  capiti  proxi" 
mi  plerumque  longissimi,  angustissimi,  subcuneati,  margine  postico  untrinque 
parum  exstante,  saepe  tamen,  praesertim  post  mortem,  contract!,  ut  reliquis 
vix  longiores  appareant.  ArticuU  insequentes  anticis  breviores  et  sensim 
latiores;  postici  subaequales,  fere  quadrati,  ut  plurimum  latiores  quam  longi, 
interdum  quasi  ex  duobus  tribusve  confusis  compositi,  satis  magni,  margine 
obtusiusculo  hinc  inde  inciso.    Articulus  ultimus  obtusus. 

Linea  utrinque  longitudinalis  articulos  majores  percurrit.  Inter  utramque 
faeturae  apparatus. " 

Leidy  (1855:444)  described  the  strobila  of  the  B.  scorpii  which  he  found  in 
Plaksa  plana  as  foUows:  "Neck  none.  Anterior  segments  cuneate  or  tri- 
angular; posterior  ones  quadrate;  each  with  an  appearance  of  three  subdivisions, 
with  the  subsegments  having  a  pair  of  generative  apertures,  in  the  course  of  a 
longitudinally  depressed  dark  colored  line,  passing  the  length  of  the  body." 
Cobbold  (1858:157)  said  of  individuals  from  Cottus  bubalis:  "Toward  the  lower 
part  of  the  so-called  neck,  the  joints  exhibited  at  the  lateral  margins  indications 
of  division,  which  became  gradually  more  defined  towards  the  tail. "  In  the 
same  connection  Krabbe  (1865:37)  stated  that,  according  to  Eschricht,  "Pen- 
dant leur  developpement  ulterieur,  I'augmentation  du  nombre  des  articles  n'est 
pas  toujours  exclusivement  due,  conune  chez  les  Taenias,  a  la  formation  de 
nouveaux  articles  engendres  par  la  tete,  mais  chez  quelques  especes,  telles  que 
les  B.  dubius,  variabilis  et  fasciatus,  [here  B.  punctatus  also]  elle  est  encore 
produite  par  la  division  transversale  qui  s'opere  dans  les  articles  deja  formes. " 
Olsson  (1867:55)  also  referred  to  multiplication  of  segments  by  transverse 
division  of  older  ones.  Loennberg  (1891 :52)  denied  this  statement  of  Olsson's, 
but,  as  pointed  out  below,  the  negation  is  applicable  to  the  posterior  mature  seg- 
ments of  this  form  at  least,  not  to  the  middle  segments  referred  to  by  the 
latter.  Linton  (1890:773)  said  "Secondary  segments  appear  at  about 
the  twelfth  segment  from  the  head.  These  are  formed  by  a  division  of  each 
segment  into  two  by  means  of  a  median  transverse  Une.  This  is  repeated  far- 
ther back  in  much  the  same  manner  as  described  under  D.  microcephalutn." 
In  this  form  such  subdivision  of  segments  to  form  daughter  segments  occurs 


102  ILUNOIS  BIOLOGICAL  MONOGRAPHS  [390 

all  along  the  strobila  from  close  behind  the  scolex  to  well  mto  the  region  showing 
the  median  row  of  reproductive  rudiments,  and  in  such  a  manner  that,  in  the 
anterior  part  of  the  strobila  at  least,  what  is  considered  to  be  a  primary  seg- 
ment, situated  between  the  most  prominent  transverse  furrows,  becomes  sub- 
divided into  2,  4,  8,  16  and  finally  32  divisions,  each  of  the  latter  accommoda- 
ting two  reproductive  rudiments.  But  it  must  be  emphasized  that  this  method 
of  formation  of  new  segments  is  not  strictly  followed  out,  since  as  it  passes 
backward  in  development,  the  primary  segment  does  not  always  contain  64 
genital  rudiments.  In  the  first  place,  some  secondarj'  or  even  tertiary  trans- 
verse furrows  become  almost  as  prominent  as  the  primary  ones,  and  secondly, 
there  is  at  the  same  time  considerable  further  subdivision  not  only  of  the  peri- 
pheral tissues  but  especially  of  the  rudiments  themselves.  Close  behind  the 
scolex  the  primary  segments  are  very  short  (Fig.  55),  the  first  six  to  ten  being 
divided  only  into  two  subdivisions  in  strobilae  of  moderate  size,  but  into 
three  or  four  subdivisions  in  the  largest  chains.  Farther  back  this  pro- 
cess of  segmentation  takes  place  gradually;  but  division  is  usually  seen  to 
occur  more  readily  and  quickly  in  the  anterior  part  of  the  primary  segment  or 
of  its  major  subdivisions,  i.e.,  secondary  or  tertiary,  than  in  its  posterior  part — 
occasionally  however  the  reverse  being  the  case.  Thus  in  general  there  is  a 
sort  of  dominance  of  the  anterior  end  of  the  segment,  which  one  might  call  a 
zooid  in  the  sense  in  which  Child  uses  the  word,  over  its  posterior  end 
as  regards  metamerism.  While  this  method  of  formation  of  segments 
is  further  obscured  by  the  fact  that  often  one  sees  intercalated  amiong  primary 
segments,  showing  these  features  well,  others  which  seem  to  lag  behind  in 
division  and  are  hence  younger,  and  that  in  much  elongated  strobilas  it  is  still 
more  difficult  to  distinguish  between  primary  and  secondary  transverse  furrows, 
owing  to  their  being  quite  smoothed  out  especially  medially,  the  whole  plan 
is  sufficiently  clear  to  warrant  its  being  described  with  the  definiteness  here 
given.  Figures  56  and  57  will  give  a  better  idea  perhaps  of  the  whole  method 
of  segmentation  than  this  description.  While  in  figure  55  the  primary  seg- 
ments are  indicated  by  asterisks,  in  figures  56  and  57  the  whole  drawing  is  in 
each  case  that  of  a  primary  segment.  Under  the  heading  of  the  reproductive 
system  below  it  will  be  seen  that  in  the  mature  portion  of  the  strobila  the  most 
prominent  transverse  furrows  are  described  as  coming  approximately  every 
eighth  or  sixteenth  genital  segment.  This  is  due  to  the  fact  that  the  secondary 
and  tertiary  furrows,  respectively  those  dividing  the  primary  segments  into 
two  then  four  parts,  become  quite  as  pronounced  as  the  primary  ones,  thus 
making  it  very  difficult  to  follow  this  plan  of  segmentation  beyond  the  region 
of  differentiation  of  the  genital  rudiments. 

At  least  three  prominent  longitudinal  grooves  run  thruout  the  median  and 
posterior  portions  of  the  strobila  on  each  surface,  even  cutting  thru  the  posterior 
borders  in  many  places.  Their  course  is  not  regular  and  they  are  accompanied 
by  numerous  other  shorter  and  m.ore  irregular  grooves,  some  of  which,  but  not 
aU,  are  due  simply  to  lateral  contraction  of  the  segments. 


391] 


PSEUDOPHYLLIDEA  FROM  FISHES— COOPER 


103 


The  following  table  gives  a  list  of  measurements  of  representative  speci- 
mens in  alcohol: 


Total  length  in  mm. 

234 

173 

130 

51 

677 

♦233 

*180 

Length  of  scolex 

1.20 

1.07 

0.81 

1.14 

1.11 

5.00 

0.85 

Breadth  of  terminal 

disc 

0.30 

0.33 

0.26 

0.33 

0.28 

0.29 

0.27 

Breadth  at  middle 

0.35 

0.32 

0.30 

0.37 

0.31 

0.11 

0.22 

Breadth  at  base 

0.28 

0.27 

0.24 

0.35 

0.26 

0.11 

0.16 

Length  of  first 

segment 

0.14 

0.16 

0.09 

0.18 

0.33 

1.83 

0.44 

Length  of  posterior 

segment 

0.85 

0.46 

0.35? 

0.57 

? 

0.54? 

0.81 

Breadth  of  same 

1.83 

1.12 

0.53? 

0.92 

? 

1.70 

0.99 

Maximum  breadth  of 

strobila 

2.50 

1.60 

1.05 

1.57 

3.35 

2.80 

1.51 

♦Somewhat  stretched  during  fixation. 


Since  Lonnberg  (1891:52)  described  the  cuticula  of  the  species  there  has 
been  no  mention  of  it  in  the  literature,  so  far  as  the  writer  is  aware.  It  was 
found  to  be  5m  in  thickness  and  composed  of  two  layers,  the  outer  of  which  is 
about  two-fifths  of  the  whole  thickness  and  is  made  up  of  rather  stout,  closely 
set  "cirri"  which  stain  much  more  readily  than  does  the  inner  more  homo- 
geneous and  lighter  layer.  These  cirri  seem  to  he  on  a  distinct  membrane  since 
their  proximal  (central)  ends  are  all  even  and  distinguishable  in  some  places 
as  dark  granules.  In  sections  stained  more  deeply  than  those  which  show  the 
inner  layer  as  a  single  homogeneous  stratum,  the  latter  is  divided  into  two 
layers,  the  outer  of  which  is  less  deeply  stained  than  the  inner  and  about  one- 
half  as  thick  or  one-fifth  of  the  thickness  of  the  whole  cuticula.  The  wavy 
nature  of  the  cuticula  and  the  basement  membrane  is  as  described  by  Lonnberg, 
but  in  many  places  the  membrane  is  separated  from  the  cuticular  musculature 
by  a  very  thin  clear  space  barely  distinguishable  with  high  powers.  The 
cuticula  covering  the  scolex  is  about  4ju  thick,  the  difference  between  it  and 
that  over  the  proglottides  being  due  to  a  thinner  homogeneous  stratum.  The 
outer  layer  of  the  cuticula  is  not  modified  to  form  spinelets  on  the  posterior 
borders  of  the  proglottides,  nor  on  the  edges  of  the  terminal  disc,  as  in  C.  crassi- 
ceps,  but  the  pseudociha  are  somewhat  longer  and  relatively  stouter  on  the 
scolex  and  anterior  segments  than  elsewhere. 

The  subcuticula,  from  25  to  30/i  in  thickness,  has  the  nuclei  of  its  spindle- 
shaped  cells  arranged  at  various  levels  so  that  the  space  between  the  cuticula 
and  the  vitelhne  follicles  is,  excepting  for  its  outer  one-third,  well  filled  with 
them  (Fig.  84). 

The  chalk-bodies,  described  by  Lonnberg,  were  not  studied  in  Hving  mater- 
ial; but  spherical  spaces  which  were  evidently  occupied  by  them  before  they 
were  dissolved  out  by  the  acetic  acid  of  the  fixing  agent,  were  found  to  be  more 


104  ILUNOIS  BIOLOGICAL  MONOGRAPHS  [392 

numerous,  as  Lonnberg  stated,  in  the  cortical  than  in  the  medullary  paren- 
chyma. In  the  scolex,  however,  they  are  somewhat  more  numerous  than  in  the 
strobila,  in  both  of  which  locations  they  attain  a  diameter  of  13/x. 

Lonnberg  (1891:53)  gave  a  good  description  of  the  musculature  of  the 
species,  while  Liihe  (1897a:747)  referred  to  that  of  the  posterior  border  of  the 
proglottis  in  the  discussion  of  the  arrangement  of  the  muscles  of  the  whole 
order.  In  addition  to  corroborating  the  findings  of  these  authors,  it  was 
noticed  by  the  WTiter  that  the  fibres  of  the  transverse  series  are  mostly  con- 
fined to  the  very  short  regions  between  the  sets  of  reproductive  organs  and 
are  most  numerous  just  ahead  of  the  prominent  segmental  furrows  mentioned 
above,  this  appljong  to  both  the  inner  and  outer  lots.  Towards  the  median 
line  each  layer  of  longitudinal  muscles  is  about  35/i  in  thickness  and  composed 
of  bundles  of  various  sizes,  in  which  the  fibres  are  \try  closely  arranged.  The 
outer  longitudinal  muscles,  the  extension  of  which  into  the  posterior  borders 
of  the  segments  immediately  behind  the  scolex  are  only  weakly  developed,  are 
in  the  scolex  confined  almost  completely  to  very  thin  bands  situated  close  to 
the  cuticular  musculature  in  the  edges  of  the  bothria,  as  described  elsewhere 
by  the  writer  (1914a:92)  for  E.  globulijorme. 

Lonnberg  (1891 :54)  described  the  ner\-ous  system  so  well  that  Uttle  needs 
to  be  added.  The  foremost  four  large  branches  from  the  brain  complex  were 
not  found  to  be  relatively  as  large  as  those  shown  in  Lonnberg's  Figure  la,  and 
the  commissiure  appeared  to  be  divided  into  two,  not  distinctly  separated, 
frontal  strands,  the  whole  depth  of  which,  including  the  space  between  them, 
was  not  as  much  as  that  shown  in  his  Figure  Ic.  In  the  strobila  the  chief  ner\'e 
strands,  each  from  15  to  25/i  in  diameter,  are  situated  towards  the  ventral  side 
of  the  medulla  and  at  the  jimctions  of  the  lateral  and  median  quarters  of  the 
latter,  as  shown  in  figure  84. 

The  excretory  system  of  B.  scorpii  was  described  in  detail  by  Fraipont 
(1881:8),  while  Lonnberg  (1891:53)  added  some  further  notes  on  its  structure, 
the  former,  however,  working  on  living  material  in  which  the  canals  are  much 
more  readily  seen.  In  good  toto  preparations  the  "canaux  descendants" 
may  be  easily  seen  in  segments  showing  the  reproductive  rudiments  as  well  as 
farther  forward.  Owing  to  a  mere  accident,  temporary  preparations  showing 
the  details  of  the  reticulum  of  descending  canals  in  great  detail  were  made  by 
the  writer  with  more  or  less  constant  success.  When  some  pieces  of  a  strobila 
were  being  transferred  from  synthetic  oil  of  wintergreen  to  a  slide  for  the  pre- 
paration of  toto  mounts  by  the  further  addition  of  x>'lol-damar,  they  suddenly 
became  opaque  white  and  remained  so  for  some  time  after  the  damar  and  cover- 
glass  had  been  added.  This  opacity  was  found  to  be  due  to  air  having  been 
drawn  into  the  excretory  canals  not  only  thru  their  cut  ends  but  thru  the 
foramina  secundaria.  But  since  the  superficial  reticulum  and  all  the  finer 
canals  were  filled  with  air,  nothing  of  the  arrangement  of  the  larger  canals 
could  be  made  out  until  a  short  time  had  elapsed,  or  until  the  preparation 
had  been  heated  slightly.  Then  the  air  in  the  smaller  canals  became  replaced 
by  the  xylol-damar,  and  the  larger  canals  stood  out  as  very  distinct  silver 


393]  PSEUDOPHYLLIDEA  FROM  FISHES— COOPER  105 

threads.  This  sort  of  preparation  is  unfortunately  not  permanent,  since 
after  a  few  minutes  all  of  the  canals  disappear,  excepting  the  very  largest 
which  can  still  be  followed  as  in  ordinary  toto  mounts.  The  results  of  this 
method  of  demonstrating  the  excretory  canals  are  shown  in  figure  61,  a  camera 
lucida  drawing  made  while  the  canals  were  disappearing  from  view.  Three 
of  Fraipont's  large  "canaux  descendants"  can  be  seen  together  with 
much  of  the  anastomes  among  them  and  at  least  two  branches  to  foramina 
secundaria.  The  largest  and  most  median  canal  has  a  diameter  of  50/x.  But 
contrary  to  what  was  stated  by  Fraipont  (1881:9,11),  only  six  of  these  main 
channels  were  found  close  to  the  ventral  layer  of  longitudinal  muscles  in  the 
medullary  parenchyma,  and  not  six  for  each  surface  of  the  strobila.  Lonnberg 
stated,  and  correctly  too,  that  their  number  is  very  variable  as  is  their  size 
and  course,  the  whole  forming  a  complicated  reticulum  showing  the  typical 
"island  formation."  As  regards  the  termination  of  the  excretory  vessels 
at  the  posterior  end  of  the  strobila,  the  writer  confirms  Fraipont's  (1881 :10) 
statement  that:  "  Chez  un  sujet  qui  a  deja  perdu  des  proglottis,  les  gros  canaux 
longitudinaux  sont  rompus  au  niveau  du  bord  libre  posterieur  du  dernier  seg- 
ment. Les  uns  communiquent  directement  avec  I'exterieur,  les  autres  ne 
sont  renfermes  et  se  terminent  en  cul-de-sac."  But  no  cases  were  met  with 
in  the  material  at  hand  in  which  it  could  be  considered  that  no  segments  had 
been  lost.  Towards  the  scolex  the  six  vessels  gradually  come  closer  and  closer 
together  until  in  the  first  segments  they  may  appear  for  short  distances  in 
two  sets  of  three  each,  dorsoventrally  situated;  but  farther  on  become  lost 
in  their  anastomoses.  Entering  the  scolex  there  may  be  seen  four,  three,  or 
two  main  canals,  but  they  cannot  be  followed  as  such  thru  many  sections, 
since  they  soon  break  up  into  the  reticulum  mentioned  by  Fraipont  as  ramifying 
thruout  the  scolex. 

Of  the  generative  organs  the  earliest  writers  were  able  to  discern  only  the 
external  openings  ("oscula")  and  the  uteri  which,  showing  their  contained, 
dark  brown  eggs  thru  the  body  wall  as  a  longitudinal  series  of  dark  punctations, 
gave  origin  to  the  specific  names  of  Zeder  (1800)  and  Rudolphi  (1802  and  1810). 
Concerning  these  characters  Miiller  (1788:6)  wrote  as  follows: 

"Margines  corporis  depressi  intersectione  articulorum  crenati  apparent; 
oscula  in  anterioribus  articulis  nulla  adsunt,  in  posterioribus  vera  altera  in 
pagina  port  in  macula  albida  nigricantes,  in  altera  papilla  alba  subelevata, 
punctaque  seu  globuli  utrinque  dispalati,  qui  ovula.  Oscula  seu  pori  non 
seriem  rectam  in  corpore.  Taeniae  sed  hinc  et  ilHnc  divergentem  constituunt, 
alterum  in  centro  articuU,  alterum  in  intersectione  constituum.  ArticuU 
postici  reliquis  latiores  punctis  utrinque  dispersis  medio  autem  coacer- 
vatis  papillullamque  exhibentibus  repleti  sunt;  horum  coacervatio  oculo  nudo 
punctum  centri  nigrum  offert,  armatus  vero  ovula  seu  globulos  e  membrana 
ovata  pellucida  punctulis  nigricantibus  impleta  constantes  discemit. " 
Rudolphi  (1810:50)  described  them  in  these  words: 

"SinguH  enim  articuK  in  superficie  dorsaU  nodulum  orbicularem,  simpHcem 
vel  dupHcem,  subelevatum,  vel  albidimi  vel  fuscescentem  aut  nigrescentem 


106  ILUNOIS  BIOLOGICAL  MONOGRAPHS  [394 

exhibent;  in  superficie  autem  ven trail  nodulus  simplex  vel  duplex,  pariter,  sed 
minus,  exstans,  quasi  perforatus  videtur;  corporeque  pellucido  nodulis  illis 
linea  corporis  media,  plerumque  tamen  irregularis  oritur.  Noduli  aperti 
ovaria  sistunt,  ovisque  ellipticis  mediocribus  referti  sunt,  haec  etiam  saepe 
circa  eosdem  eflfusa  srmt. "  From  these  descriptions  it  is  to  be  seen  that  while 
Miiller  made  correct  observations  concerning  the  relations  between  the 
positions  of  the  genital  openings  and  the  transverse  furrows  mentioned  above, 
Rudolphi  considered  the  ventral  surface  to  be  that  on  which  the  openings  of 
the  cirrus  and  vagina  are  situated  and  the  dorsal  that  on  which  the  uterus 
opens  to  the  exterior. 

Van  Beneden  (1850)  seems  to  have  been  the  first  writer  to  describe  the 
anatomy,  with  however  some  errors  of  interpretation  as  pointed  out  by  Lonn- 
berg  (1891).  After  Lonnberg's  the  best  and  practically  the  only  description 
of  the  genitalia  was  given  by  Matz  (1892:105),  Ariola  (1900:394)  and  Luhe 
(1910:25)  obviously  copying  in  part  at  least  from  him. 

The  earliest  traces  of  the  reproductive  rudiments  appear  in  toto  mounts 
about  35  to  40mm.  from  the  tip  of  the  scolex.  From  this  region  backwards 
they  increase  in  size,  but  so  slowly  that  in  large  strobilas  there  may  be  an  inter- 
vening stretch  of  at  least  225mm.  before  the  genital  sinus  appears.  Then 
the  rudiments  differentiate  very  quickly,  the  first  eggs  appearing  in  the  uterus- 
sac  about  2mm.  farther  on  in  one  toto  mount  made.  In  the  largest  strobila 
at  hand  the  first  genital  sinuses  were  seen,  when  the  worm  was  examined  in 
alcohol,  about  375mm.  from  the  tip  of  the  scolex,  and  the  first  traces  of  eggs 
showed  thru  the  ventral  body  wall  about  20mm.  farther  on. 

Van  Beneden  (1850:162)  was  the  first  to  mention  the  relations  between  the 
external  segments  and  the  sets  of  reproductive  organs.  He  said:  "Dans 
chaque  anneau,  il  y  a  deux  ou  trois  appareils  males  et  femelles  complets;  je 
pense  que  ces  anneaux  se  divisent  encore  plus  tard,  de  maniere  a  n'avoir  plus 
qu'  un  appareil  dans  chaque  animal,"  [here  "animal"  is  evidently  a  misprmt 
for  "anneau"];  and  further  in  his  footnote  referring  to  the  superscript  after 
"complets":  "J'ai  vu  des  anneaux  qui  en  contenaient  jusqu'a  six."  In  his 
figure  4,  PI.  XXI,  he  showed  four  parts  of  the  strobila  containing  evidently 
three  or  four  sets  of  reproductive  organs  in  each  segment,  with  the  latter  sub- 
dividmg  so  that  two  sets  appeared  in  each  subsegment  in  the  fourth  part  of 
the  figure.  Leidy  described  the  posterior  segments  of  B.  scorpii  as  "  ... 
quadrate;  each  with  an  appearance  of  three  subdivisions,  with  the  subsegments 
having  a  pair  of  generative  apertures,  in  the  course  of  a  longitudinally  depressed, 
dark  colored  fine,  passing  the  length  of  the  body."  Linton  (1890:733)  re- 
ferred to  "the  phenomenon  which  the  posterior  segments  present  of  being 
welded  together  in  groups  of  three  or  four,  an  appearance  which  is  quite  char- 
acteristic of  the  posterior  segments  and  which  has  been  alluded  to  in  various 
descriptions  of  the  species,"  while  further,  in  connection  with  the  apertures 
of  the  reproductive  organs:  "In  the  middle  of  the  strobila  there  sometimes 
appear  to  be  as  many  as  four  or  more  papillae  to  a  single  segment;"  and  with 
reference  to  the  specimens  from  Lophopsetta  maculata:  "...  toward  the 


J: 
.5^ 


395]  PSEUDOPHYLLIDEA  FROM  FISHES— COOPER  107 

posterior  end  of  the  body  the  adult  segments  are  arranged  in  groups  of  from 
four  to  six  simple  segments,  as  if  the  latter  were  partially  fused  together,  which 
is  another  characteristic  of  this  species."  From  these  statements  and  the 
further  fact  that  the  posterior  proglottides  have  been  described  as  trapezoidal 
(Stossich),  quadrate  (Rudolphi,  Linton),  subquadrate  (Diesing),  or  at  most, 
broader  than  long  (Rudolphi) — actually  about  twice  as  broad  as  long  from 
Linton's  (1890:732,  734)  description — it  is  evident  that  the  groups  of  four 
sets  of  reproductive  organs  (much  less  frequently  three,  five  or  six)  shown  here 
in  figures  59  and  60,  and  separated  from  each  other  by  grooves  which  in  al- 
cohoHc  material  appear  to  be  complete,  have  been  considered  to  constitute 
the  ripe  proglottides.  But,  as  pointed  out  by  Lormberg,  the  lesser  transverse 
furrows  are  only  "greater  WTinkles  or  foldings  of  the  surface"  and  do  not  cut 
in  deep  enough  to  cause  the  parts  immediately  ahead  to  stand  out  distinctly 
like  the  posterior  borders  of  the  proglottides  of  other  species,  e.g.,  C.  cras- 
siceps.  Such  posterior  borders,  with  their  accompanying  "complete"  trans- 
verse furrows,  do  occur,  however,  but  only  at  considerable  intervals.  One  case 
is  shown  in  figure  95,  where  it  will  be  noticed  there  is  no  such  distinct  separation 
of  the  proglottis  from  the  next  one  ahead.  So  far  as  the  writer  is  aware,  this 
has  been  pointed  out  only  by  Liihe  (1910:25)  who  said:  "...  in  reifen 
GUederstrecken  Hegen  zwischen  zwei  vollig  durchgehenden,  aber  auch  nur 
wenig  hervortretenden  oberflachhchen  Querfurchen  in  der  Kegel  16  sehr  kurze 
Genitalsegmente,  die  ausseriich  voneinander  nur  durch  Zackenbildungen  des 
Seitenrandes  gescheiden  sind. "  In  this  coimection  it  should  also  be  noted 
that  in  his  description  of  Fimbriariafasciolaris  (PaUas),  a  taenioid  from  various 
water  birds,  Wolffhiigel  (1900:94)  remarked  that  it  is  comparable  to  B.  scorpii 
in  that  "eine  bis  ins  aussergewc  hnUche  gestiegerte  Anzahl  von  Geschlechts- 
apparaten  in  einer  Proglottis  sich  folge. " 

In  a  considerable  length  of  one  toto  mount  of  this  form  there  were  foimd 
ahead  of  and  including  the  region  of  differentiation  of  the  reproductive  rudi- 
ments the  following  consecutive  number  (from  behind  forwards)  of  genital 
segments  between  the  most  pronounced  transverse  furrows,  that  is  in  the 
primary  segments  in  question:  67,  82,  101,  107,  90,  111,  116,  using  as  the  cri- 
terion of  a  genital  segment,  especially  ahead  of  the  region  of  differentiation, 
the  aggregation  of  nuclei  in  the  median  Hne  which  will  go  to  form  the  central 
organs  and  ducts  of  the  sytem.  There  is,  however,  much  dif&culty  in  making 
these  counts  on  account  of  rudimentary  or  intercalated  groups  of  nuclei  which, 
judging  from  conditions  to  be  seen  in  the  region  of  differentiation,  may  or  may 
not  form  complete  sets  of  genitaUa,  and  above  all  of  the  further  subdivision 
of  many  of  these  rudiments,  which  otherwise  proceeds  in  quite  the  same  man- 
ner (Fig.  57)  as  that  of  the  external  segments  in  the  anterior  part  of  the  strobila. 
Furthermore,  there  may  often  be  seen  either  in  the  anterior  part  of  the 
region  of  differentiation  or  much  farther  ahead  (Fig.  57)  a  lateral  doubling 
of  the  developing  genitaUa.  But  since  no  case  was  met  with  of  two  sets  of 
reproductive  organs  in  a  ripe  genital  segment,  it  was  concluded,  especially 
because  of  the  great  infrequency  of  this  dupUcation,  that  one  or  the  other  nidi- 


108  ILUNOIS  BIOLOGICAL  MONOGRAPHS  [396 

ment  eventually  gets  the  upper  hand  and  develops  at  the  expense  of  the  other. 
This  is  borne  out  by  the  fact  that  in  half  the  cases  one  rudiment  was  much 
larger  than  the  other.  The  above  mentioned  groups  of  rudiments  were  divided 
and  subdivided  by  less  and  less  pronounced  transverse  furrows  in  the  following 
manner: 

67  82  101 


43  24  35  47  54  47 


24    19    10    14  14    21     18    13    16  16    14    12    12    20    12     15 

This  continued  imtil  eventually  the  groups  of  four  (or  five,  rarely  six)  sets 
of  genitalia  of  the  authors  could  be  made  out.  Each  of  these  in  turn  was 
seen  to  be  divided  into  two  groups  of  two  sets  each,  so  that  each  lateral  crenu- 
lation  corresponded  to  two  (or  three)  of  them,  i.e.,  to  the  l-32nd  division  de- 
scribed above  (Fig.  57).  In  ripe  segments  this  arrangement  may  obtain  or  the 
segment  may  divide  again  peripherally,  so  that  each  crenulation  then  corres- 
ponds with  one  set  of  genitalia  (Figs.  59  and  60).  The  latter  figures  show 
that  "complete"  transverse  furrows  are  present  between  every  8  or  9  (some- 
times 7,  or  apparently  even  3,  4,  5  or  6!)  genital  segments.  However,  other 
more  relaxed  strobilas  in  alcohol  showed  complete  furrows  only  every  16  to  17 
sets  of  genital  segments,  there  often  being  a  group  of  5  instead  of  the  much 
more  common  group  of  four — but  in  the  same  neighborhood  of  the  strobUa 
just  as  complete  grooves  every  8,  9  or  10  sets.  This  shows  that  a  grouping  of 
the  genital  segments  into  lots  of  approximately  16,  as  mentioned  by  Liihe 
(1910:25)  is  so  irregular  that  it  can  scarcely  be  said  to  occur  "as  a  rule,"  and 
that  the  peculiar  method  of  segmentation  of  the  anterior  end  of  the  strobila 
mentioned  above  (p.  102)  is  very  difficult  to  follow  with  any  degree  of  certainty 
beyond  the  region  of  differentiation  of  the  genital  rudiments. 

The  genital  sinus  is  situated  on  a  low  papilla  (Fig.  59)  on  the  dorsal  smiace, 
in  the  median  line  and  from  one-half  to  two-thirds  of  the  length  of  the  genital 
segment  from  its  anterior  border,  while  the  uterine  opening  on  the  ventral  sur- 
face is  located  much  farther  forward,  even  at  the  bottom  of  the  groove  corres- 
ponding to  the  indentation  of  the  edge  of  the  strobila,  separating  the  crenula- 
tions  mentioned  above.  The  sinus  itself  is  circular  in  outline  and  from  40  to 
45/i  in  diameter  by  15  to  20/x  in  depth.  At  its  bottom  the  cirrus  and  vagina 
open  close  together,  the  latter  immediately  behind  the  former,  thru  a  sec- 
ondary sinus  or  ductus  hermaphroditicus,  the  walls  of  which  are  often  found 
protruding  thru  the  opening  of  the  larger  vestibule  as  if  to  form  part  of  a  func- 
tional cirrus  (Fig.  95). 

The  testes  are  arranged  in  two  lateral  fields  in  the  medullary  parenchyma, 
as  pointed  out  by  Lonnberg,  and  are  continuous  from  segment  to  segment,  altho 
they  show  some  tendency  towards  division  interproglottidally.  The  nimiber 
was  given  by  Matz  (1892:106)  as  about  76,  with  their  size  as  40.8/Lt,  but  here  it 
was  found  to  be  from  30  to  60,  while  their  size  was  35  to  70^,  60  being  the 


397]  PSEUDOPHYLLIDEA  FROM  FISHES— COOPER  109 

commonest  measurement.  The  vas  deferens,  filled  with  sperms,  forms  a  com- 
pact mass  of  coils  about  0.18  by  0.10mm.  in  size,  lying  irregularly  to  the  right 
or  left  of  the  uterine  duct  or  slightly  behind  the  sac  and  immediately  alongside 
the  cirrus-sac,  as  shown  in  Fig.  71.  The  ductus  ejaculatorius  portion  of  the 
vas  deferens  within  the  cirrus-sac,  that  is,  that  part  occupying  the  lowermost 
one-third  of  the  latter,  has  a  diameter  of  from  4  to  6/*.  The  middle  stretch  of 
the  duct  often  expands  to  13/i,  while  the  distal  part,  the  cirrus  proper,  has  a 
maximum  length  of  65/i  with  a  width  of  14ju.  Matz  gave  the  dimensions  of  the 
organ  (?  the  cirrus-sac)  as  100  by  SOju.  The  cuticula  Uning  the  cirrus  is  pseudo- 
cihated  on  its  inner  (functionally  outer)  surface,  somewhat  as  is  that  on  the 
external  surface  of  the  worm.  The  cirrus-sac  is  located  at  right  angles  to  the 
dorsal  surface  (Fig.  95)  and  extends  only  a  short  distance  into  the  medulla,  as 
compared  to  other  species.  It  is  ovoid  in  shape,  with  the  narrower  end  towards 
the  cloaca,  and  from  115  to  120ju  in  length  by  from  75  to  SO/x  in  diameter.  Its 
wall  is  composed  of  an  inner  thick  layer  of  circular  muscles  and  a  very  thin 
outer  layer,  the  fibres  of  which  are  directed  somewhat  obliquely,  the  whole 
being  8)u  in  thickness.  As  pointed  out  by  Lonnberg  and  shown  in  figure  95, 
the  organ  is  peculiar  in  that  its  wall  is  coated  both  externally  and  internally 
mth.  a  thick  layer  of  nuclei  which  are  doubtless  mostly  myoblastic  in  their 
nature.  An  aggregation  of  nuclei  at  the  lower  pole  of  the  sac,  surrounding 
the  vas  deferens  and  continuous  with  the  layer  of  nuclei  on  the  outside  of  the 
pouch,  are  too  numerous  to  be  considered  as  myoblastic  nuclei  only.  They  do 
not  seem  to  be  mentioned  either  by  Lonnberg  or  Matz.  Their  arrangement 
would  indicate  that  they  are  possibly  prostatic  in  their  nature,  the  whole  struc- 
ture having  the  appearance  of  a  gland.  Retractor  muscles  of  the  cirrus  proper 
are  scarce.  This  fact,  taken  in  conjunction  with  the  further  fact  that  the 
wall  of  the  sac  is  quite  thick  and  powerful,  and  that  Lonnberg  saw  only  a  short 
thick  cirrus  when  protruded,  would  lend  support  to  the  view  that  the  latter 
is  quite  small  and  not  very  important  from  a  functional  standpoint.  Concern- 
ing copulation  in  this  species  Lonnberg  said:  "Es  ist  daher  wahrscheinlich, 
dass  die  normale  Befruchtung  so  vor  sich  geht,  dass  das  Sperma  in  den  Sinus 
genitalis  hinausgepresst  wird,  und  davon  entweder  passiv  durch  die  Kontrak- 
tion  der  Sinus  genitalis  oder  aktiv  durch  eigene  Bewegung  in  die  Vagina  gelangt. 
Sowohl  die  eine  als  die  andere  Weise  scheint  recht  moglich  zu  sein,  well  die 
Miindung  der  Vagina  ganz  neben  derjenigen  des  Penis  gelegen  ist. " 

The  vagina  opens  into  the  ductus  hermaphroditicus  close  behind  the  cirrus. 
From  there  it  proceeds  close  along  the  cirrus-sac  to  its  lower  end,  and  then 
turns  back  to  pass  over  the  ovarian  isthmus  and  into  the  generative  space.  Its 
diameter  is  13)u,  while  its  wall  is  composed  of  a  cuticula  5ju  in  thickness  and  a 
thin  layer  of  circular  muscles.  Its  cuticula  is  retained  until  the  point  of  union 
with  the  oviduct  is  reached,  where  the  lumen  narrows  down  suddenly  to  one- 
half  the  former  diameter  (Fig.  105).  The  ovary  with  a  width  of  0.35mm.  and 
a  length  of  0.15mm.,  is  somewhat  irregularly  "biscuit-shaped"  (Fig.  71)  and 
situated  close  to  the  posterior  border  of  the  segment  or  protruding  slightly 
into  the  segment  behind.    It  is  composed  of  short  tubular  lobules  of  varying 


110  ILLINOIS  BIOLOGICAL  MONOGRAPHS  398] 

size.    In  transections  it  is  seen  to  be  "concave  towards  the  surface  bearing 
the  genital  openings"  owiag  to  the  fact  that  the  ventrally  situated  isthmus  is 
,  quite  narrow  and  thick  and  consequently  not  well  separated  from  the  lobular 
wings  which  extend  thruout  the  whole  dorsoventral  diameter  of  the  medulla 
and  also  somewhat  enfold  the  former  posteriorly  in  the  median  line.    Ova  from 
the  isthmus  are  15/i  in  diameter,  while  their  nuclei  and  nucleoli  average,  re- 
spectively, 7  and  3m.    The  oocapt  is  quite  muscular,  and  35/x  in  diameter.    The 
oviduct  proceeds  dorsally  for  a  short  distance  only  before  it  is  joined  by  the 
vagina  at  a  vestibule  into  which  the  oviduct  itself  opens  (Fig.  105)  by  a  narrow 
slit  much  as  in  C.  crassiceps.    The  wall  of  the  duct  is  composed  of  an  epithelium, 
in  which  no  cell-boundaries  could  be  made  out,  but  provided  with  cilia  directed 
towards  the  uterus.    The  oviduct  continues  dorsally  for  a  short  distance  with 
the  same  structure  and  diameter,  namely  ISju,  to  take  on  the  vitelline  duct 
dorsal  to  the  anterior  edge  of  the  isthmus.    The  vitelline  follicles  are  arranged 
in  the  cortical  parench)mia  in  two  lateral  fields  (Fig.  84)  which  are,  however, 
slightly  connected  with  each,  other  dorsally  and  ventrally  in  the  median  line 
by  a  few  isolated  follicles.    No  large  foUicle  such  as  that  described  by  Matz  in 
the  neighborhood  of  the  ovary  was  seen  in  the  material  studied.    The  follicles 
vary  somewhat  in  size,  but  average  35  to  55)Lt  in  diameter,  are  very  closely 
crowded  together — so  as  to  obscure  in  toto  preparations  the  testes  beneath 
them — and  continuous  from  proglottis  to  proglottis.    The  latter  fact  makes  it 
difficult,  if  not  somewhat  unnecessary,  to  state  the  number  for  each  genital 
segment,  but  using  Matz's  method  of  multiplying  the  average  number  seen 
in  transections  by  that  seen  in  sagittal  sections  (here  the  average  of  several 
segments  was  taken),  the  number  varies  from  350  to  540,  or  440  on  the  average. 
Matz  gave  490  as  the  number.    Two  main  vitelline  ducts  proceed  from  opposite 
sides  of  the  genital  segment  and  unite  in  the  antero -dorsal  portion  of  the  genera- 
tive space  to  form  a  very  short  common  duct  which  from  the  amount  of  yolk 
it  usually  contains  may  act  as  a  vitelline  reservoir,  altho  the  same  function  is 
shared  even  to  a  larger  degree  by  the  much  coiled  and  distended  proximal 
portions  of  the  separate  ducts.    A  few  cases  were  met  with  in  which  small 
ducts  laden  with  yolk  came  from  follicles  clearly  belonging  to  the  genital  seg- 
ment foUowing.    This  condition  is,  however,  not  surprising  in  view  of  the  con- 
tinuous arrangement  of  the  foUicles  themselves.    The  diameter  of  the  common 
duct  at  its  point  of  union  with  the  oviduct  is  about  8/i.    The  very  voluminous 
shell-gland  is  situated  dorsal  to  the  ovarian  isthmus  close  behind  the  cirrus-sac, 
with  a  depth  of  85m  and  width  of  115m.    The  uterine  duct  is  quite  capacious 
since  it  is  composed  of  many  coils  extending  thruout  the  whole  depth  of  the 
medulla  immediately  ahead  of  the  ovary.    Proximally  it  is  lined  with  a  syncitial 
epitheUimi  which  distaUy  becomes  much  attenuated.    While  it  is  usually 
situated  in  the  median  line  it  may  alternate  from  right  to  left  as  a  whole  accord- 
ing as  the  vas  deferens  does  so  on  the  opposite  side  of  the  proglottis,  the  uterus- 
sac  in  such  cases  remaining  in  the  median  line.    As  above  noted,  the  uterus-sacs 
were  called  "  ovaries  "  by  the  early  writers.    They  were  seen  thru  the  body  wall 
to  be  filled  with  the  characteristic  dark  brown  eggs  forming  dark  patches  or 


399]  PSEU DOPEY LLIDEA  FROM  FISHES— COOPER  111 

punctations,  hence  the  specific  names  bipunciata  and  punctata.  In  this  species 
the  uterus-sacs  were  described  by  Rudolphi,  Leuckart  (1819:41),  et  al.,  as  ar- 
ranged in  a  single  row,  in  a  double  row,  or  alternating  thruout  the  strobila. 
They  were  likewise  found  to  alternate  irregularly  from  side  to  side  (Fig,  60) 
(e.g.,  r,  1, 1,  r,  r,  1,  r,  1, 1,  r,  r,  1,  etc.)  or  to  be  more  medially  situated  (1,  m,  1, 
m,  m,  m,  m,  1,  m,  r,  r,  m,  1,  1,  m,  m,  etc.)  but  never  in  two  rows,  ex- 
cepting in  a  very  few  immature  genital  segments  (Fig.  57),  unless  the  alternating 
condition  in  much  contracted  strobilas  is  considered  as  such.  While  the  sac 
has  a  diameter  of  about  0.18mm.  when  the  first  eggs  appear  in  its  lumen,  it 
may  reach  a  length  of  0.35mm.  and  a  transverse  diameter  of  0.22mm.  or  about 
one-sixth  of  that  of  the  proglottis.  The  combined  uterus-sac  and  uterine  duct 
may  in  many  cases  occupy  more  than  one-third  of  the  width  of  the  segment. 
The  hindermost  segments,  in  which  the  uterus-sacs  may  be  gorged  with  eggs 
to  a  diameter  of  0.65mm.,  separate  from  the  chain  evidently  in  pairs,  the  Unes 
of  division  taking  place  at  the  furrows  between  the  larger  crenulations  men- 
tioned above.  No  detached  proglottides  were  found  free,  however,  in  the  intes- 
tine of  the  host,  altho  Olsson  (1867:55)  recorded  having  found  such,  while 
Weinland  (1858:9)  said  that,  according  to  Eschricht,  the  species  "which  Uves 
in  the  sculpin  of  the  Baltic  (Cottus  scorpius)  throws  off  its  whole  chain  of  joints 
every  year  and  then  sends  out  a  new  one  from  the  neck. "  Like  that  of  the 
distal  portion  of  the  uterine  duct  the  wall  of  the  sac  is  composed  of  a  much 
attenuated  epitheUum  from  the  basement  membrane  of  which  the  nuclei, 
separated  by  wide  intervals,  project  into  the  lumen  like  bosses.  The  uterus- 
opening  is  situated  ventrally  in  the  middle  of  the  uterus-sac,  and  with  regard 
to  the  external  segmentation  either  in  the  middle  of  the  larger  (double)  seg- 
ment or  in  the  groove  separating  it  from  the  next  ahead  or  behind.  Circular 
in  outline  and  50/x  in  diameter,  it  is  surrounded  by  an  area  of  radiating  nuclei, 
thought  by  Lonnberg  to  be  possibly  of  the  nature  of  a  gland  for  the  secretion 
of  a  material  of  use  in  the  passage  of  the  eggs  to  the  exterior.  The  actual 
opening  is  formed  by  the  rupture  of  a  membrane  guarding  the  outlet,  which 
has  a  thickness  of  from  15  to  30n,  (cf.  C.  crassiceps). 

The  fresh  egg  is  elHpsoidal  in  shape,  dark  brown  in  color,  and  measures  from 
66  to  80/i  in  length  by  43  to  45/x  in  transverse  diameter.  The  shell  was  ob- 
served to  be  about  9/x  thick  in  living  material  and  not  provided  with  an  oper- 
culum. No  mature  eggs  showing  the  six  hooks  of  the  oncosphere  were  met 
with  in  fresh  material  in  the  field. 

Nothing  was  discovered  regarding  the  intermediate  host  or  hosts  of  this 
species,  not  even  in  the  way  of  food-contents,  for  the  stomachs  and  intestines 
of  the  few  sea-ravens  examined  were  all  found  to  be  empty.  Linton  (1890 :732) 
gave  as  the  food  of  Lophopsetta  maculata  and  Limanda  ferruginea,  from  which 
he  recorded  Dibothrium  puitctatum  Rud.,  "several  species  of  AnneUds,  frag- 
ments of  Squilla,  and  several  specimens  of  a  species  of  Margarita. "  No  speci- 
mens smaller  than  about  25mm.  in  length  were  obtained.  According  to 
Udinsky's  abstract,  Pilat  (1906:191),  working  on  B.  scorpii  from  Raja  clavata 
of  the  Black  Sea  (the  only  case  of  the  species  having  been  found  in  a  selachian 


112  ILLINOIS  BIOLOGICAL  MONOGRAPHS  [400 

fish,  so  far  as  the  writer  is  aware)  estabHshed  the  fact  '*dass  seine  Larven  in 
den  verschiedenen  Fischen  oder  Tieren,  welche  von  Rochen  (Raja  clavata) 
gefressen  werden,  sich  befanden. " 

From  the  foregoing  description  it  is  to  be  seen  that  this  form  is  very  closely 
related  to  the  B.  scorpii  (Miiller)  of  Europe,  altho  in  many  respects  it  is  so 
different  as  to  almost  warrant  the  erection  of  a  new  species  to  accommodate  it. 
However,  on  accoimt  of  the  fact  that  several  forms  of  the  European  species 
have  been  reported,  namely,  B.  scorpii  forma  bubalidis  and  formu  motdlae  by 
Lonnberg  (1889:32  and  1893:13)  and  those  from  Rhombus  maximtis  and  Cottus 
quadricornis  by  Schneider  (1902a :14  and  1903:75),  it  is  considered  that  here  in 
America  one  finds  the  same  species  as  has  been  found  in  Europe.  And  from  a 
comparison  of  the  measurements  given  above  with  those  given  by  Leidy  (1855: 
444)  and  Linton  (1890:732,  734  and  1897:430),  it  seems  that,  little  as  one  can 
rely  on  external  measurements,  they  also  point  to  definite  differences  of  habit 
as  this  worm  is  found  in  different  host  species  on  this  side  of  the  Atlantic. 

In  the  table  given  below  under  B.  claviceps  the  important  diagnostic  data 
of  this  form  are  placed  alongside  those  of  the  European  species  for  the  sake  of 
comparison. 

The  material  studied  consisted  of  lots  Nos.  191,  196,  197,  198,  287,  and  288 
of  the  writer's  collection  from  the  intestine  of  Hemitripterus  americanus 
(Gmelin),  No.  17.57  of  the  Collection  of  the  University  of  Illinois  from  the 
same  host,  and  No.  17.56  of  the  same  collection  from  Myoxocephalus  aeneus  (?). 

DIBOTHRIUM  ANGUSTATUM  (Rudolphi),  species  inquirenda 

Linton  (1901a  :454,  474)  reported  this  species  from  Poronotus  triacanthus, 
the  butter-fish,  and  Merluccius  bilinearis,  the  sUver  hake.  Regarding  speci- 
mens from  the  former  he  said:  "9.  Dibothrium  angustatum  Rudolphi.  Intes- 
tine [PL  XXIV,  figs.,  269,  a,  b,  c] 

Thirty-seven  j'oung  strobiles,  August  21,  1899.  These  agree  closely  with 
Diesing's  synopsis  of  this  species:  'Head  elongate,  tetragonal,  slender,  with 
oblong  lateral  bothria;  neck  very  short.  First  segments  elongated,  very  nar- 
row, succeeding  segments  shorter,  subquadrate. ' 

The  outline  of  the  head  varies  with  the  state  of  contraction,  but  the  pre- 
vailing form  is  linear,  oblong  or  somewhat  clavate.  Segments  slender,  almost 
cylindrical,  shghtly  enlarged  at  their  posterior  ends.  Dimensions  of  an  alco- 
holic specimen  in  millimeters:  Length  of  head,  1.16;  breadth,  anterior  0.33, 
greatest  breadth  0.33,  posterior  0.19.  Another:  Length  of  head  1.21,  breadth 
anterior  0.22,  greatest  breadth  0.26,  posterior  0.17.  Longest  head  measured 
1.92mm.  in  length  to  the  first  distinct  segment.  The  strobiles  are  linear  or 
nearly  so  and  measured  about  25mm.  in  length. " 

The  species  was  originally  created  by  Rudolphi  (1819:476)  to  accommodate 
two  specimens  from  Scorpaena  scrofa.  The  diagnosis  he  gave,  however, 
apphes  not  only  to  the  anterior  end  of  B.  scorpii  when  much  elongated,  but 
also  to  younger  specimens  of  the  same.  "Ovaria  speciei  praecedentis  [B. 
punctatus — mihi]  cui  haec  etiam  valde  affinis  est,"  from  the  same  description 


401]  PSEU DOPEY LLI DBA  FROM  FISHES— COOPER  113 

Strengthens  this  fact,  as  does  Diesing's  (1850:594)  remark  that  D.  angustatum 
"specie!  praecedentis  forsan  mera  varietas."  Dujardin  (1845:614)  considered 
the  species  to  be  synonymous  with  Leuckart's  (1819:41)  B.  affinis  which  the 
latter  pointed  out  was  "ahnlich  dem  B.  punctatus,"  only  smaller  and  more 
elongated.  An  interesting  point  that  Leuckart  brought  out,  which  further 
strengthens  the  resemblances  to  B.  scorpii,  was  that  "Em  grosseres  GUed 
wechselt  gewohnlich  mit  einem  kleineren  ab."  "Ovaries"  were  described  as 
being  in  one  row  and  nearer  the  anterior  than  the  posterior  edge  of  the  proglot- 
tis, which  with  the  general  characters  of  the  segments  and  scolex  point  to  B. 
affinis  being  merely  a  variety  of  B.  scorpii.  Later  Diesing  (1863:240)  added 
to  the  diagnosis:  "Aperturae  genitalium  laterales" — that  is  surficial,  and  not 
lateral  in  the  sense  of  being  marginal,  as  it-is  now  used.  Parona  (1887:320) 
gave  a  description  of  the  external  features  which  differed  little  from  those  al- 
ready pubhshed  and  even  with  the  four  figures  accompanying  it  does  not  permit 
one  to  separate  the  species  from  B.  scorpii.  Matz  (1892 :121)  merely  listed  the 
species,  while  Blanchard  (1894:701)  included  it  in  his  genus  Bothriocephilus. 
Ariola  (1896:263,  272,  280)  made  a  few  brief  statements  regarding  the  form,  in 
which,  besides  giving  the  length  and  breadth  of  the  strobila  as  8.5  to  9cm.  and 
0.9mm.  respectively  and  the  dimensions  of  the  eggs  as  70  by  51/x,  he  said  that 
'  'Osservo  che  esso  tan  to  per  le  dimension!  del  corpo,  quanto  per  i  caratteri  dello 
scolice  nuUa  ha  di  comune  col  B.  punctatus,  che  ha  una  lunghezza  totale  di  circa 
50cm.,  e  quindi  constituisce  una  specie  propria,  quale  appunto  I'hanno  ritenuta  il 
Rudolphi,  il  Parona,  ed  altri  elmintologi. "  He  placed  the  species  (p.  280) 
among  those  of  the  genus  Bothriocephalus  Rud,  with  dorsoventral  bothria,  in 
his  classification  of  the  family  "  BothriocephaUdae  s,  str. "  Stossich  (1898 :1 16) 
reported  the  species  from  Scorpaena  porcus  at  Trieste,  but  added  nothing  of 
diagnostic  value,  while  Ariola  (1900:419)  continued  to  hold  his  former  opinions 
concerning  the  form:  "E  con  cio  cade  il  dubbio  di  Diesing  e  di  Cams,  che 
cioe  il  B.  angustatus  possa  riguardarsi  come  una  varieta  del  Botriocephalo 
puntato,  il  quale  ultimo  ne  e  assai  lontano,  oltre  che  per  notevoli  differenze  di 
tutto  il  corpo,  per  i  botridii  dorsoventrali. "  Linton's  report  of  the  species  has 
been  referred  to;  and  finally  Shipley  recognized  the  species  in  "Numerous  frag- 
ments taken  from  the  intestine  of  the  salmon,  Salmo  solar. " 

Thus  it  is  evident  that  in  the  literature  there  are  not  sufficient  data  to  enable 
one  to  state  whether  this  form  is  a  separate  species  or  not,  but  much  that 
points  to  its  being  only  a  variety  of  the  quite  variable  B.  scorpii.  Nor  was  the 
writer  lead  to  any  conclusions  by  an  examination  of  the  material  which  Linton 
(1901 :474)  described  from  Merluccius  bilinearis,  contained  in  No.  6646,  U.  S. 
N.  M.  It  was  found  to  be  very  fragmentary  and  immature,  but  on  the  whole 
to  suggest  B.  scorpii  in  miniature.  A  to  to  preparation  of  one  of  the  widest 
pieces  showed  no  traces  of  the  reproductive  rudiments,  but  six  chief  excretory 
vessels,  arranged  quite  like  those  in  B.  scorpii,  the  median  pair  being  the 
largest,  and  all  of  them  quite  straight  as  from  pronounced  elongation  of  the 
whole  stretch  of  segments.  On  the  other  hand,  the  long  narrow  condition  of  the 
scolex  seemed  to  be  persistent  in  the  material;  but,  since  no  strobilas  of  B. 


114 


ILLINOIS  BIOLOGICAL  MONOGRAPHS 


[402 


scorpii  nearly  so  small  were  at  hand  for  study,  the  writer  cannot  say  that  such 
characters  do  not  exist  in  the  latter.  On  the  whole  it  seems  best  to  consider 
B.  angustatus  a  species  inquirenda  until  more  and  better  material  can  be  studied 
and  comparisons  made  between  the  form  that  appears  here  in  America  and  that 
which  is  foimd  in  Europe. 


BOTHRIOCEPHALUS  CLAVICEPS  (Goeze  1782) 
[Figs.  19,  20,  23,  72,  85,  96] 


1722 

Vermis  multimembris 

Leeuwenhoek 

1722  ; 

;490 

1780 

Taenia  anguillae  (part.) 

MuUer 

1780 

:208 

1782 

Taenia  claviceps 

Goeze 

1782  ; 

:414 

1786 

Taenia  claviceps 

Batsch 

1786 

:211 

1786 

Taenia  anguillae 

Batsch 

1786 

-.233 

1790 

Taenia  anguillae 

Gmelin 

1790 

:3078 

1790 

Taenia  claviceps 

Schrank 

1790 

:46 

1800 

Rhytelminthus  anguillae 

Zeder 

1800 

:215 

1801 

Taenia  claviceps 

Rudolph! 

1801  : 

103 

1802 

Taenia  anguillae 

Bosc 

1802 

:307 

1803 

Rhytis  claviceps 

Zeder 

1803 

:293 

1810 

Bothriocephalus  claviceps 

Rudolph! 

1810 

:37 

1816 

Bothrioc.  claviceps 

Lamarck 

1816 

:582 

1819 

Bothrioc.  claviceps 

Rudolph! 

1819 

:  136,  472 

1819 

Bothrioc.  claviceps 

Leuckart 

1819 

:49 

1824 

Bothrioc.  claviceps 

Nitzsch 

1824 

:97 

1844 

Bothrioc.  claviceps 

Belibigham 

1844 

:251 

1845 

Bothrioc  claviceps 

Dujardin 

1845 

:618 

1848 

Bothrioc.  claviceps 

Siebold 

1848 

:147 

1850 

Dibothriutn  claviceps 

Diesing 

1850 

:589 

1853 

Bothrioc.  claviceps 

Baird 

1853 

:89 

1854 

Dibothriutn  claviceps 

Diesing 

1854  : 

:578 

1859 

Dibothrium  claviceps 

Polonio 

1859 

:225 

1859 

Dibothrium  claviceps 

MoUn 

1859 

:8 

1863 

Dibothrium  claviceps 

Diesing 

1863 

:241 

1867 

Bothrioc.  claviceps 

Olsson 

1867 

:56 

1885 

Bothrioc.  claviceps 

Cams 

1885  ; 

:120 

1892 

Bothrioc.  claviceps 

Matz 

1892 

:108 

1893 

Bothrioc.  claviceps 

Olsson 

1893 

:  16-17 

1896 

Bothrioc.  claviceps 

Ariola 

1896  ; 

:280 

1899 

Bothrioc.  claviceps 

Luhe 

1899  : 

:43 

1900 

Bothrioc.  claviceps 

Ariola 

1900  ; 

:393 

1902 

Bothrioc.  claviceps 

Fuhrmann 

1902 

:  441,  447 

1910 

Bothrioc.  claviceps 

Ltlhe 

1910  : 

:25 

403]  PSEUDOPHYLLIDEA  FROM  FISHES— COOPER  115 

Specific  diagnosis:  With  the  characters  of  the  genus.  Large  cestodes  up 
to  540mni.  long  by  2  to  3  wide.  Scolex  small,  elongate,  but  usually  found 
contracted  to  an  almost  spherical  shape;  0.5  to  l.Snmi.  long  by  0.3  to  0.5  wide 
at  the  middle.  Prominent  terminal  disc.  First  segments  thick,  short  and 
crowded;  middle,  oblong;  posterior,  or  ripe  proglottides,  usually  2mm.  broad 
by  0.5  to  0.7  long,  often  quadrate,  arranged  in  groups  of  two,  between  which 
the  transverse  furrow  is  not  prominent;  other  transverse  furrows  well  marked. 

Cuticula  1  to  2ju  thick.  Calcareous  bodies  very  scarce.  Main  longitudinal 
muscles  not  in  bundles.    Four  to  six  chief  longitudinal  excretory  vessels. 

No  genital  papilla;  genital  cloaca  funnel-shaped,  midway  between  anterior 
and  posterior  borders  of  the  proglottis.  Vagina  opens  immediately  behind 
the  cirrus-sac;  no  separation  between  common  cloaca  and  hermaphroditic 
duct. 

Testes  large,  subspherical,  averaging  58jli  long,  64  wide  and  60  deep;  50 
to  60  for  each  proglottis.  Coils  of  vas  deferens  loose,  close  behind  uterus-sac, 
0.35mm.  wide  by  0.07  long.  Cirrus-pouch  ellipsoidal,  127  to  145At  deep  by 
81  to  104  in  diameter,  thin-walled. 

Ovary  compact,  0.45. to  0.55mm.  in  width,  0.055  in  length  and  0.18  in 
depth;  isthmus  quite  thick,  ventral.  Oocapt  30/i  in  diameter.  Vitelline 
follicles  not  separated  into  two  fields  on  either  surface,  450  to  720  in  numba:, 
45,  80  and  85/x  in  length,  width  and  depth,  respectively;  vitelline  reservoir 
large,  175  by  65^.  Shell-gland  posterodorsal,  alternating  irregularly  from 
right  to  left  opposite  the  vas  deferens.  Uterine  duct  quite  voluminous,  be- 
tween ovary  and  uterus -sac.  Uterus-sac  transversely  elongate,  occupying 
one-third  or  more  of  the  transverse  diameter  of  the  proglottis,  usually  larger 
towards  the  side  bearing  the  opening;  openings  form  a  zig-sag  ventral  row. 

Egg,  58  to  63jLt  long  by  37  to  40  wide,  without  opercula;  light  in  color,  show 
only  faintly  thru  the  body-wall. 

Habitat:  In  the  pyloric  portion  of  the  intestine  of  the  host. 


*^  — ... 


116 


ILUNOIS  BIOLOGICAL  MONOGRAPHS 


[404 


HOST 

LOCALITY 

COLLECTOR 

AUTHORITY 

AnguiUa  vulgaris 
AnguiUa  vulgaris 
Anguilla  vulgaris 

Leeuwenhoek 

Diesing 
Diesing 
Dujardin 

1850  :  590 

Zeder 

1850  :  590 

Rennes 

Dujardin 

1845  :  618 

Anguilla  vulgaris 

Patavia 

Molin 

Diesing 

1863  :  241 

Anguilla  vulgaris 

Onegasee,  Rus- 
sian Finland 

Kessler 

Schneider 

1902  :  17 

AnguiUa  vulgaris 

Sinus  Codani; 
L.  Holland, 
Sweden 

Olsson 

Olsson 

1867  :  56 

AnguiUa  vtdgaris 

Venice 

Ninni 

Stossich 

1891  : 8 

AnguiUa  vulgaris 

Ostsee,  Wame- 
miinde  and  Unter- 
wamow-Rostock 

Braun 

Braim 

1891  :  55 

AnguUla  vtdgaris 
AnguiUa  vulgaris 

Matz 

1892  :  109 

Geneva 

Parona 

Ariola 

1900  :  394 

?  Anguilla  vulgaris 

Nancy 

Prenant 

Zschokke 

1896  :  818 

?  AnguiUa  vulgaris 

Konigsberg  and 
Memel 

Muehling 

Muehling 

1898  :  35 

Anguilla  vulgaris 

Peninsula  of 
Porkala,  Finland 

Schneider 

Schneider 

1902  :  15 

AnguiUa  vtdgaris 

Trfike  Garda,  Italy 

Largaiolli 

Ariola 

1900  :  394 

AnguiUa  acutirostris 

Ireland 

Bellingham 

Bellingham 

1844  :  251 

AnguiUa  acutirostris 

Siebold,  Coll. 

Baird 

1853  :  90 

Brit.  Museum 

AnguiUa  anguilla 
Anguilla  migrator ia 

Germany 

Liihe 

1910  :  25 

Kroyer 

Stiles  and 

1912  :  124 

HassaU 

Mtiraetta  anguilla 
Muraena  anguilla 

Borke 

Goeze 

1782  :  414 

Gryphswald 

Rudolphi 

Rudolphi 

1810  :  38 

Mtiraena  anguilla 

Kais.-konig. 
nat'l  kab. 

Leuckart 

1819  :  49 

Muraena  anguilla 

Horja,  Scania; 
I^kes  Halen  and 
Refundsjon,  Jemt- 
land,  Sweden; 
Bonan,  Gulf 
Bothnia 

Olsson 

Olsson 

1893  :  16 

Muraena  cassini 

Naples 

Rudolphi 

Rudolphi 

1819  :  472 

Anguilla  rostrata 

Chamcook  L., 

Cooper 

Cooper  (the 

present 

New  Brunswick 

paper) 

Eupomotis  gibbosus 

Walnut  L., 
Michigan 

H.  B.  Ward 

i»          »> 

Gasteroskus  bispinosus 

Woods  Hole, 
Mass. 

V.  N.  Edwards 

f>          f> 

On  account  of  the  fact  that,  accordmg  to  Rudolphi  (1810:31),  Miiller 
(1780:208)  ascribed  four  suckers  to  his  Taenia  angiiillae,  we  must  look  to 
Goeze  (1782:414)  for  the  first  accurate  description  of  the  species.  Under 
the  name  "Der  Kolbenkopf,  Taenia  daviceps"  he  gave  the  following  diagnosis: 


405]  PSEU DOPEY LLIDEA  FROM  FISHES— COOPER  117 

"In  den  Gedarmen  eines  Aals  (Muraena  Anguilla),  worin  sie  der  Graf 
von  Borke  gefunden.  Nach  dem  Berichte  dieses  genauen  Beobachters  4 
Fuss  lang.  So  lang  hat  er  ihn  noch  in  keinem  Fische  bemerkt.  Mit  der  Lupe 
lassen  sich  die  beiden  langlichten  Saugwarzen  an  dem  kolbenartigem  Kopfe 
dieses  Wurms  besser,  als  unter  dem  Komposito  bemerken.  Sie  sind  deutlicher 
gegliedert,  als  die  Bandwiirmer  aus  den  Hechten.  Die  Endphalangen  mit 
vielen  kleinen  Knotigen  angefiillt.  Dies  die  Aggregate  von  Eiem,  deren  sie 
im  Wasser,  worin  sie  aufbehalten  wurden,  eine  unzahliche  Menge  von  sich 
gegeben  hatten.  Die  Glieder  kann  der  Wurm  kurz  und  lang  machen,  wie 
aus  der  Zeichnung  erhellet.  Dieses  ist  also,  wie  der  Graf  hinzusetzt,  eine 
besondere  Art  von  Taenien. "  Gmelin  (1790:3078)  retained  the  specific  name, 
anguUlae,  and  described  the  worm  as  follows : 

"T.  capite  sessili  distincto  crassiore,  articulis  oblongis  vage  torulosis: 
osculis  duobus  in  uno  latere.  .  .  .  Habitat  in  anguillae  intestinis,  ad  4 
pedes  longa,  capite  anterius  truncate,  articulis  8  proxunis  longiore,  articulis 
circiter600,  prioribus  subquadratis,  latitudinelongitudinem  duplo,  posteriori  bus 
orbicularibus:  latitudine  longitudinem  octuplo  superante. "  Rudolphi  (1810: 
38)  gave  the  diagnosis  which  has  been  followed  by  most  of  the  authors  since, 
excepting  as  regards  the  position  of  the  bothria : 

^^ Caput  polymorph um,  articulis  aliquot  proximis  simul  sumtis  longius, 
cisque  crassius,  subtetragonimi,  sub  motu  saepe  utrinque  aequale,  subovale, 
plerumque  depressum,  postice  increscens,  anticeque  non  raro  margine  tumido, 
untrinque  exstante,  terminatum.  Foveae  marginales,  sive  in  latere  dextro 
et  sinistro  (capitis  depressi  margine)  sitae,  oblons;ae,  sub  motu  variabiles,  an- 
tice  plerumque  latiores,  mox  planiusculae,  mox  magis  profundae.  Collum 
nullum.  Corporis  plani  et  antrorsum  angustissimi  articuli  varii:  primi  breves; 
insequentes  longiores,  tandem  subquadrati,  quorum  singuli  antrorsum  angus- 
tiores,  margine  postico  tumidiusculo,  utrinque  exstante;  articulis  ultimus 
obtusus.  Posteriorum  margo  lateralis  alter  media  saepe  parte  foramen  dis- 
tinctum  habet.  Ovarium  in  eonmdem  articulonmi  media  parte  sacciforme, 
saepe  maculam  rubescentem  refert"  or  in  more  condensed  form  (1810:37; 
1819:136): 

"B.  capite  oblongo,  bothriis  marginalibus,  collo  nullo,  articuUs  anterioribus 
brevisshnis,  mediis  oblongis,  reliquis  subquadratis,  margine  postico  tumido." 
F.  S.  Leuckart  (1819:49)  was  unable  to  find  a  scolex  shaped  like  that  figured 
by  Goeze,  but  concerning  the  material  he  studied  he  remarked: 

"Der  Kopf  lang,  grossentheils  fast  viereckt,  zuweilen  auch  ganz  keulen- 
formig;  bei  einigen  vorn  mehr  abgestumpft  und  der  Rand  scharf  hervorragend. 
Einige  hatten  nmd  um  den  Kopf  uber  den  Gruben  eine  schmale  Vertiefung. 
Glieder  alle  vie!  breiter  als  lang,  sehr  schmal,  besonders  die  vorderen,  zusam- 
mengezogen.  Ovarien  habe  ich  an  keinem  Examplare  wahrnehmen  konnen. " 
While  Nitzsch  (1824:97)  added,  erroneously,  "...  die  Geschlechtmiin- 
dungen  am  Seitenrade,"  Bellingham  (1844:251)  merely  listed  the  worm  from 
the  eel  as  above  recorded.  Dujardin  (1845:618)  made  valuable  additions  to 
the  descriptions  of  the  species  but  Diesing  (1850:589  and  1863:241),  Baird 


118  ILLINOIS  BIOLOGICAL  MONOGRAPHS  [406 

(1853:89),  Olsson  (1867:56)  and  Carus  (1885:120)  did  Httle  more  than  list 
the  worm  in  their  various  works;  so  that  it  remained  for  Matz  (1892:108)  to 
give  the  first  comprehensive  description  of  the  anatomy,  particularly  of  that 
of  the  reproductive  organs.  Later,  apart  from  reports  by  various  workers 
of  the  finding  of  the  species,  Olsson  (1893:16)  noted  the  infrequent  occurrence 
of  the  worm  in  the  host,  an  increase  in  the  number  of  segments  by  means  of 
transverse  division  and  the  variable  form  of  the  scolex;  Ariola  (1896:268,  272, 
273,  280;  1900:393),  Liihe  (1899:43),  Braun  (1900:1676)  and  Fuhrmann  (1902: 
441, 447)  dealt  with  it  from  a  systematic  standpoint;  and  fiinally  Liihe  (1910:25) 
gave  a  short  diagnosis,  mostly  after  Matz,  in  placing  it  in  his  latest  classifica- 
tion of  the  Pseudophyllidea. 

According  to  Dujardin  this  species  ranges  in  length  from  25  to  540mm.  (Ze- 
der),  but  Luhe  (1910:25)  gave  the  length,  presumably  of  average  individuals, 
as  from  100  to  200mm.  with  a  breadth  of  about  2mm.  While  the  specimens 
from  Anguilla  rostrata  examined  by  the  writer  were  quite  small,  fragmentary, 
immature  and  much  elongated,  the  longest  piece,  however,  not  exceeding 
20mm.,  two  from  Eupomotis  gibbosus,  measured  155mm.  in  length  by  2.9  in 
maximum  breadth,  and  were  much  contracted,  as  indicated  in  figure  19  of 
the  scolex.  The  latter,  according  to  the  authors,  varies  in  preserved  material 
from  an  almost  spherical  shape,  as  mentioned  by  Goeze  and  Leuckart  and 
shown  in  the  latter's  Fig.  28,  Taf.  II,  to  the  much  elongate  form  shown  in 
Matz's  Fig.  16,  Taf,  VIII.  The  tip  of  the  organ  may  be  protruded,  flattened 
or  even  replaced  by  a  shallow  groove  which  passes  from  bothrium  to  bothrium 
in  the  sagittal  plane,  depending  on  the  degree  of  contraction  or  relaxation. 
These  differences  are  brought  out  here  in  figure  23,  the  latter  being  more  like  that 
of  Matz.  In  either  case  a  slight  notch  is  to  be  seen  on  the  surficial  edges  of  the 
terminal  disc,  while  the  bothria  are  deeper  immediately  behind  these  than  poster- 
iorly where  they  pass  insensibly  on  to  the  base  of  the  scolex.  The  segments  have 
been  variously  described,  but  Rudolphi's  (1819:136)  mention  of  "  ...  arti- 
culis  anterioribus  brevissimis,  mediis  oblongis,  reliquis  subquadratis,  margine 
postico  tumido "  may  be  considered  as  indicating  their  condition  in  average 
states  of  contraction.  Matz  stated  that  "Die  gleich  hinter  ihm  [the  scolex] 
beginnenden  Proglottiden  sind,  wenn  nicht  contrahiert,  ein  Viertel  oder  ein 
Fiinftel  so  lang  als  der  Scolex.  Die  geschlechtsreifen  Gheder  sind  2mjn.  breit 
und  ein  halb  bis  drei  Viertel  mm.  lang;  man  bemerkt  an  den  Gliedern  haufig 
sekimdare  Teilung,  vde  bei  B.  punctatus  dadurch  wohl  bewirkt  wd,  dass  der 
Rand  des  vorhergehenden  uber  das  nachfolgende  Glied  sich  nicht  erhebt, 
hochstens  deutet  eine  rings  herumgehende  Furche  die  Grenze  an,  wie  es  auch 
bei  B.  imnctakis  der  Fall  ist;"  while  Liihe  (1910:25)  said  ''Die  letzten 
Proglottiden  nahezu  quadratisch  oder  sogar  langer  wie  breit. "  In  the  material 
from  Eupomotis  gibbosus  all  of  the  anterior  proglottides  were  found  to  be  much 
broader  than  long,  on  account  of  the  contraction  of  the  strobilae,  while  those 
in  detached  pieces  were  from  four  to  five  times  as  broad  as  long,  as  shown  in 
figure  72.  Apart  from  Matz,  Olsson  (1893:16)  and  Liihe  (1910:25)  have  noted 
secondary  division  of  segments,  or  as  Olsson  stated  the  case,  "Hos  denna  art 


4071 


PSEUDOPHYLLIDEA  FROM  FISHES— COOPER 


119 


framtrader  mycket  tydligt  och  allmant  en  forokning  af  ledema  genom  tvar- 
delning;  man  finner  nasten  hvarje  led  genom  en  svagt  framtradande  tvarlinie 
deladt  i  tva  lika  led,  hvartdera  med  hanliga  och  honliga  organ,  cm  moderledet 
haft  sadana.  Afven  die  konlosa  leden  visa  samma  forokningssatt, "  which, 
however,  is  what  Dujardin  observed  in  1845  when  he  said  that  "On  remarque 
en  ontre  que  souvent  les  articles  sont  tellement  unis  deux  a  deux,  que  chaque 
couple  parait  n'en  faire  qu'un  seul  avec  une  vide  transverse  et  deux  appareils 
genitaux,  I'un  devant  I'autre."  This  pairing  of  the  ripe  proglottides,  also 
shown  here  in  figure  72,  is  due  to  the  manner  of  segmentation  which  is  like 
that  described  for  B.  scorpii,  only  quite  regular,  since  the  reproductive  rudi- 
ments appear  relatively  farther  forward  in  the  strobila  and  seem  to  be  more  sta- 
ble in  development.  Concerning  this  method  of  increase  in  the  number  of 
segments  for  this  species  Liihe  (1910:25)  said,  "Zwei  aufeinanderfolgende 
Genitalsegmente  ausserlich  haufig  nur  unvolkommen  geschieden,  indessen 
fehlen  durchgehende  Querfurchen  auf  den  Flachen  nie  auf  so  weite 
Strecken  wie  bei  B.  punctatus."  On  account  of  the  great  degree  of  con- 
traction of  the  only  two  strobilas  provided  with  scolices  at  hand,  the 
primary  segments  were  not  followed  with  entire  satisfaction  very  far  beyond 
the  scolex,  but  the  first  two  were  seen  to  be  divided  into  four  sub- 
segments  each — the  first  one,  shown  in  figure  19,  including  the  four  segments 
to  the  *  at  the  side  of  the  figure — with  some  indication  of  the  next  division 
which  would  result  in  eight  to  the  primary  segment;  the  third  into  eight,  and 
so  on.  There  were  indications  posteriorly,  however,  that  the  primary  segment 
consists  of  at  least  32  genital  segments  or  proglottides,  but  as  in  B.  scorpii 
the  furrows  separating  sets  of  16,  8  and  4  genitaha  become  almost  as  prominent 
as  those  between  the  groups  of  32,  while  even  those  separating  pairs  are  not 
as  faint  as  Olsson  (1893:16)  stated  and  showed  in  his  Fig.  I,  Tab,  II.  At  all 
events  it  should  be  emphasized  that  the  furrows  are  more  distinct  and  con- 
sequently the  proglottides  better  defined,  at  least  externally,  than  in  B.  scorpii. 
In  the  material  studied  the  segments  quickly  broaden  behind  the  scolex  to 
2mm.  at  a  distance  of  20mm.  from  the  latter,  and  then  very  gradually  attain 
the  maximum  width.  The  following  table  gives  the  measurements  of  the 
three  largest  specimens  at  hand: 


Length  of  strobila 

155mm. 

150mm. 

43mm. 

Maximum  breadth 

2.9 

2.9 

2.0 

Length  of  scolex 

0.44 

0.46 

0.46 

Breadth  of  terminal  disc 

0.22 

0.20 

0.22 

Breadth  at  middle 

0.28 

0.3a 

0.33 

Depth  of  terminal  disc 

0.20 

0.20 

0.20 

Depth  at  middle 

0.26 

0.20 

0.40 

Depth  posteriorly 

0.27 

0.27 

0.46 

Width  of  ripe  joints 

2.0 

1.6 

Length  of  ripe  joints 

0.40  to  0.50 

0.4  to  0.6 

The  cuticula,  between  only  1  and  Ijx  in  thickness,  is  difficult  to  distinguish 
from  the  finely  matted  and  comparatively  dense  cuticular  musculature.    The 


120  ILLINOIS  BIOLOGICAL  MONOGRAPHS  [408 

subcuticula  is  from  25  to  40//  deep,  and  the  nuclei  of  its  cells  are  confined 
to  their  central  halves.  No  calcareous  bodies  were  seen  in  the  rather  fine- 
meshed  parenchyma,  altho  according  to  Braun  (1896:1262)  such  were  found 
by  Kiichenmeister  in  this  species. 

The  musculature  is  comparatively  weakly  developed.  The  frontal  fibres  are 
fine,  scattered  thruout  the  medulla  and  between  the  longitudinal  fibres;  while 
the  same  may  be  said  of  the  sagittal  series.  The  longitudinal  fibres  are  com- 
paratively few  and  widely  separated  from  each  other,  and  as  stated  by  Matz, 
"are  not  arranged  in  bundles. " 

The  chief  nerve  strands,  about  17/i  in  diameter,  are  situated  distinctly  dorsal- 
ly  in  the  medulla  and  betwe'^u  the  lateral  quarters  of  the  transverse  diameter 
of  the  segment. 

Matz  described  two  main  excretory  vessels,  between  which  is  located  the 
nerve  strand,  on  each  side  of  the  body,  while  Dujardin  had  previously  stated 
that  there  were  four  on  each  side.  In  the  sections  made  three  were  seen  to 
follow  a  constant  course  on  each  side,  the  nerve  strand  passing  between  the 
more  median  pair.  They  are  shown  in  figure  85.  The  medianmost  pair  are 
greatly  flattened  as  they  pass  close  against  the  uterus-sac  somewhat  ventrally. 

Up  to  the  time  when  Diesing  (1863:241)  incorrectly  described  the  genital 
apertures  as  marginal  and  alternating,  the  only  references  to  the  reproductive 
organs  of  this  species  were  to  the  uterus-sacs  which,  being  gorged  with  eggs 
in  the  posterior  segments,  could  be  seen  thru  the  thin  body-wall  in  the  medial 
line.  Carus  (1885:120)  failed  to  correct  Diesing's  error,  so  that  it  remained 
for  Matz  (1892:109)  to  give  the  first  and  apparently  only  adequate  description 
of  the  genitalia,  dealing  with,  hov/ever,  only  the  differences  between  them  and 
those  of  B.  scorpii.  The  earliest  traces  of  the  reproductive  rudiments  appear 
about  5mm.  from  the  tip  of  the  scolex  while  the  first  eggs  in  the  uterus-sacs 
come  at  about  55mm.  While  the  opening  of  the  uterus  is  well  towards  the 
anterior  edge  of  the  segment,  that  of  the  genital  cloaca  is  midway  between  the 
anterior  and  posterior  borders.  There  is  no  papilla,  the  opening  being  a  low 
funnel-shaped  depression  in  which  there  is  no  distinction  between  the  external 
portion  of  the  cloaca  and  the  hermaphroditic  duct. 

The  number  of  testes  as  determined  directly  is  from  50  to  69,  while  their 
average  lengths,  breadths  and  depths  are  52  to  63,u,  58  to  70,u  and  58  to  63^1 
respectively.  The  similar  data  as  given  by  Matz  are:  number,  56,  size  35  to 
47/i.  The  vas  deferens,  about  20//  in  diameter,  forms  a  mass  of  open  coils, 
lateral  to  the  cirrus-pouch  and  posterior  to  the  uterus-sac,  thus  occupying  the 
opposite  side  of  the  median  line  from  that  accommodating  the  bulk  of  the  uter- 
ine tube.  The  whole  mass  of  coils  is  about  0.35mm.  wide  and  0.07  long.  En- 
tering the  base  of  the  sac  with  a  diameter  of  8^1,  it  gradually  enlarges  until  at 
the  cirrus  proper  it  is  twice  that  size.  The  proximal  end  of  that  portion 
within  the  pouch,  however,  is  often  found  enlarged  to  form  a  sort  of  inner  semi- 
nal vesicle.  The  cirrus-sac  itself  ranges  in  length  from  127  to  145/i  and  in 
maximum  diameter  from  81  to  104.  Matz  gave  the  measurements  as  109  by 
64/x.    In  comparison  with  that  of  B.  scorpii  the  wall  is  quite  thin  and  there 


409]  PSEUDOPHYLLIDEA  FROM  FISHES— COOPER  121 

is  no  dense  layer  of  nuclei  just  within  it,  as  indicated  in  figure  96,  while  the 
retractor  fibres  and  small  amount  of  parenchyma  are  quite  loosely  arranged. 

From  its  opening  immediately  behind  the  cirrus-sac,  the  vagina  passes 
downward  and  backward  among  the  coils  of  the  uterine  duct  and  joins  the 
oviduct  at  the  dorsal  edge  of  the  ovary  just  a  short  distance  from  the  oocapt. 
At  the  middle  of  its  course  it  is  15/x  in  diameter.  The  ovary  is  from  0.45  to 
0.55mm.  wide,  about  55^  long  and  0.18mm.  deep,  being  thus  considerably 
flattened  anteroposteriorly.  The  spherical  ova  in  the  isthmus  have  an  average 
diameter  by  13jli.  The  oocapt  is  30/i  in  diameter,  while  the  oviduct  at  the 
point  of  union  with  the  vagina  is  often  slightly  narrower  than  the  vagina,  in 
fact  about  lO/z.  Large  right  and  left  vitelline  ducts  unite  in  the  median  line 
to  form  the  yolk  sac  which  is  1 75  by  65jli  in  size .  The  vitelline  follicles  with  max- 
imum lengths,  widths  and  depths  of  45,  80  and  85^,  respectively,  number  from 
450  to  720,  or  on  the  average  570  for  each  proglottis,  as  calculated  by  Matz's 
method.  They  are  not  separated  into  two  fields  on  each  surface  but  strongly 
united  around  the  reproductive  apertures,  unlike  the  B.  claviceps  of  Matz,  the  ^ 
two  ventral  fields  of  which  were  only  weakly  united  while  the  dorsalwere 
strongly  so.  The  shell-gland  is  posterodorsal  and  on  the  other  side  of  the 
median  line  from  the  vas  deferens.  The  uterine  duct  is  so  voluminous  (Fig. 
72)  that  it  crowds  the  uterus-sac  and  vas  deferens  to  the  other  side  of  the  median 
line.  It  alternates  irregularly  from  right  to  left,  as  do  the  latter.  The  sac 
itself  is  situated  in  the  anterior  half  of  the  proglottis  where  it  is  somewhat 
flattened  in  the  longitudinal  direction  and  constantly  occupies  one-third  of 
the  transverse  diameter,  as  shown  in  Matz's  Fig.  15.  The  openings,  each 
about  30/i  wide,  form  a  zig-zag  ventral  row,  since  they  are  not  exactly  in  the 
median  line  but  as  much  as  0.3mm.  apart.  Apart  from  being  somewhat  ragged 
or  villous  they  are  not  specially  noteworthy. 

While  the  eggs  of  the  European  form  have  been  given  as  from  56  to  60/*  in 
length,  they  were  here  found  to  be  from  58  to  63^  long  by  37  to  40/x  wide  when 
measured  in  the  formol  in  which  the  specimens  were  preserved.  They  are 
light  in  color  and  so  do  not  show  thru  the  body-wall  as  in  B.  scorpii. 

From  the  above  comparison  it  will  be  seen  that  altho  the  individuals  from 
Eupomotis  gibhostis  (those  from  which  the  data  were  taken)  do  not  exactly 
agree  with  the  European  species,  they  are  sufficiently  close  to  justify  their  being 
considered  the  same.  This  was  made  more  certain  to  the  WTiter  by  the  exam- 
ination of  some  fragments  of  the  European  form,  obtained  by  Professor  Ward 
from  Dr.  O.  Fuhrmann  of  Neuchatel,  Switzerland,  who  took  them  from  Anguilla 
vidgaris  in  "North  Germany."  But  it  should  be  stated  that  in  the  latter 
material  the  cirrus-sac  and  ovary  are  smaller  and  the  uterus-sac  much  larger, 
occupying  more  than  half  the  diameter  of  the  proglottis  in  many  places;  or,  the 
reproductive  organs  seem  to  become  mature  relatively  earlier,  differences  in 
degree  of  contraction  and  relaxation  being  taken  into  consideration. 

The  material  studied  consisted  of  No.  289  of  the  writer's  collection  from 
Anguilla  rostrata,  Nos.  17.33  and  16.456  from  the  collection  of  the  University 
of  IlUnois,  the  former  from  Eupomotis  gibbosus  and  the  latter  from  Anguilla 


122 


ILLINOIS  BIOLOGICAL  MONOGRAPHS 


[410 


vulgaris  (North  Germany),  and  No.  17.54  of  the  same  collection  from  Cas- 
ter os  tens  hispinosus. 

The  most  important  data  of  diagnostic  value  for  the  two  species,  B.  scorpii 
and  B.  daviceps,  are  here  given  in  the  form  of  a  table  for  the  sake  of  comparison: 


B,  scorpii 

B.  daviceps 

European  data 

Data  by  writer 

European  data 

Data  by  writer 

Length 

35-600mm. 

677mm. 

90-540mm. 

155mm. 

Breadth 

1-7 

3.35 

2-3 

2.9 

Length  of  scolex 

0.9-3.0 

1.2 

0.5-1.5      • 

0.46 

Breadth  of  scolex 

0.3-1.7 

0.35 

0.5 

0.30 

Breadth  of  posterior 

segments 

4.0 

1.8 

2 

2.0 

Length  of  same 

0.22 

0.35-0.85 

0.5-0.75 

0.5 

Number  of  genital  seg^- 

ments  per  external  seg- 

ment 

16 

8  or  16 

Less    than   in 
B.  scorpii 

See  text 

Number  of  longitudinal 

excretory  vessels 

6,  8,  12 

6 

4 

6 

Number  of  testes 

76 

30-60 

56 

50-60 

Diameter  of  same 

40.8m 

35-70M 

36-47M 

60-70/1 

Dimensions  of  cirrus-sac 

IOOxSOm 

120x80/x 

109x64/i 

145x104m 

Number  of  vitelline  fol- 

licles 

490 

350-540 

462 

450-720 

Size  of  same 

30-40m 

35-55^1 

Arrangement  of  same 

In  2  separate 

Dorsal  fields 

Dorsal  fields 

Dorsals  united; 

dorsal  fields;  2 

slightly  uni- 

united; ventral 

venTErals  uni- 

ventral fields 

ted;  2  ventral 

fields  weakly 

ted  to  same 

weakly  united 

fields  weakly 
united 

imited 

degree 

Dimensions  of  eggs 

50-80x40/i 

66-80.x43-45m 

50-60M 

58-63x37-40m 

Arrangement  of  uteri 

1  row,  alternat- 

1 row,  alternat- 

ing, or  2  row^s 

ing,  or  2rows 

Diameter  uterus  :  diam. 

Only     small 

1  :6 

1 :3-l  :2 

1  :3 

segment 

portion     of 
diameter 

Longitudinal  muscles 

Close  together 

In  bundles 

Not  in  bundles 

Not  in  bundles 

411]  PSEUDOPHYLLIDEA  FROM  FISHES— COOPER  123 

BOTHRIOCEPHALUS  CUSPIDATUS  Cooper  1917 

[Figs.  24,  25,  69,  70,  86,  102,  106,  107] 
1917        Bothriocephalus  cuspidatus  Cooper  1917  :  37 

Specific  diagnosis:  With  the  characters  of  the  genus.  Medium  sized  ces- 
todes  up  to  ISOnini.  in  length  by  2.75  in  breadth.  Scolex  large  w-ith  very  prom- 
inent terminal  disc  deeply  notched  surficially;  bothria  long  and  narrow  and 
quite  deep  posteriorly  giving  the  scolex  when  viewed  laterally  the  appearance 
of  an  arrow-head;  3.3mm.  long,  1.0  wide  at  middle,  2.5  deep  posteriorly. 
First  segments  subcuneate  and  circular  in  transection,  with  prominent  posterior 
borders;  middle  gradually  broaden  until  much  wider  than  long;  posterior  two 
to  four  and  half  times  wider  than  long,  or  1  to  2.7mm.  in  width  by  0.8  in  length. 
Posterior  end  of  strobila  usually  rounded,  even  when  segments  have  already 
become  detached. 

Cuticula  3.5jLt  thick,  subcuticula  58/x.  No  calcareous  bodies.  Longi- 
tudinal muscles  not  in  bundles.    Four  main  longitudinal  excretory  vessels. 

Genital  cloaca  median,  halfway  between  anterior  and  posterior  borders  of 
proglottis,  deep  and  funnel-shaped.  Vaginal  opening  close  behind  that  of 
cirrus;  hermaphroditic  duct  obscure. 

Testes  on  each  side  separated  into  two  fields  by  the  nerve  strand,  inner 
much  narrower  than  outer;  50  to  60  in  each  proglottis;  110,  60  and  80/i  in 
maximum  width,  length  and  depth  respectively.  Vas  deferens  a  large  compact 
mass  of  coils,  elongate  and  lateral  to  cirrus-pouch,  0.22mm.  long  by  0.16  in 
width,  alternates  irregularly  from  right  to  left.  Cirrus-sac  very  large  and 
thin-walled,  0.25mm.  in  length  (depth)  by  about  0.20  in  diameter.  Cirrus 
protruded,  135ju  long  by  85  in  diameter. 

Ovary  compact,  with  limbs  often  turned  forward,  0.60mm.  wide,  0.10  long 
and  0.13  thick;  isthmus  thick.  Oocapt  20  to  25)u  in  diameter.  Vitelline  fol- 
licles 800  to  1000;  70,  50  and  45/i  in  maximum  depth,  width  and  length,  re- 
spectively; occupying  almost  the  whole  of  the  cortex,  strongly  imited  dorsally 
and  ventrally.  Common  vitelline  duct  long  and  narrow.  Uterine  duct  con- 
fined to  one  side  of  the  median  line,  opposite  the  cirrus-sac,  alternating  irregu- 
larly from  side  to  side.  Uterus-sac  spherical,  occupying  one-third  of  the  dia- 
meter of  the  proglottis;  opening  median,  close  to  the  anterior  edge  of  the  latter. 

Eggs  ellipsoidal,  62  to  66m  long  by  42  to  45  wide,  oncospheres  not  developed 
within  uteri. 

Habitat:  Ceca  and  intestine  of  the  host. 


124 


ILLINOIS  BIOLOGICAL  MONOGRAPHS 


[412 


HOST 

LOCALITY 

COLLECTOR 

AUTHORITY 

SHzostedion  vitreum  (type 

Flat  Rock  L., 

Cooper  (the  present 

host) 

Muskoka,  Ont. 

A,  R.  Cooper 

paper) 

Stizostedion  vitreum 

Giant's  Tomb  Id., 

Georgian  Bay 

A.  R.  Cooper 

» 

SHzostedion  vitreum 

Sandusky,  Ohio 

H.  J.  VanCleave 

j> 

Stizostedion  vitreum 

New  Baltimore, 

Mich. 

H.  B.  Ward 

» 

Stizostedion  vitreum 

Port  Clinton, 

Ohio 

H.  B.  Ward 

>» 

Stizostedion  vitreum 

Put-in  Bay,  Ohio 

H.  B.  Ward 

)> 

Stizostedion  canadense 

New  Baltimore, 

Mich. 

H.  B.  Ward 

>» 

Stizostedion  canadense 

Kansas  City, 

Mo. 

H.  M.  Benedict 

» 

Hiodon  tergisus 

Havana,  111. 

H.  J.  VanCleave 

>» 

Hiodon  alosoides 

Keokuk,  Iowa 

H.  B.  Ward 

>> 

"Pickerel" 

Gillett  Grove, 

Iowa 

G.  R.  LaRue 

» 

Percina  caprodes 

Douglas  Lake, 

Mich. 

G.  R.  LaRue 

» 

Perca  flavesencs 

T<akes  Kegonsa 
and  Monona, 

Wis. 

A.  S.  Pearse 

II 

Type  specimen:  No.  174.2  of  the  writer's  collection. 
Co-type:  No.  174.3  of  the  same  collection,  deposited  in  the  collection  of  the 
University  of  Illinois. 

Type  locality :  Georgian  Bay,  Lake  Huron,  off  Giant's  Tomb  Island. 


So  far  as  the  writer  has  been  able  to  ascertain  a  description  df  this  species 
has  not  yet  been  published,  nor  have  any  bothriocephalid  cestodes  been  reported 
for  Stizostedion  vitreum  (Mitchill),  the  common  pickerel  or  wall-eyed  pike. 

In  general  appearance  this  species  does  not  arrest  attention  imtil  a  fairly 
close  examination  is  made,  since  it  is  comparatively  small  and  when  much 
relaxed  not  so  very  different,  at  least  posteriorly,  from  some  of  the  species  of 
Proteocephalus,  one  of  which  evidently  not  yet  reported,  was  found  associated 
with  it  in  the  same  host.  It  is  medium  sized,  attaining  a  length  of  about  180 
mm.  with  a  maximum  breadth  of  about  2.75mm. 

The  scolex,  on  account  of  its  comparatively  great  depth,  is  more  often  seen 
and  much  more  conspicuous  from  a  lateral  view  (Fig.  25).  Dorsoventrally 
(Fig.  24)  it  is  long  and  narrow,  showing  a  terminal  disc  well  set  off  from  the 
bothria,  while  laterally  it  is  roughly  shaped  like  an  arrow-head,  as  indicated 
by  the  specific  name  chosen,  or  somewhat  comparable  to  a  flask  or  vase  pro- 
vided with  a  low  conical  lid  (the  terminal  disc).    The  bothria  are  long,  narrow 


413]  PSEUDOPHYLLIDEA  FROM  FISHES— COOPER  125 

and  elongate  oval  in  lateral  view,  the  greatest  depth  being  near  the  posterior 
end.  They  are  separated  by  a  prominent  lateral  groove  on  each  side,  which 
extends  from  the  anterior  edge  of  the  first  segment  to  a  dorsoventral  groove 
just  behind  the  disc.  The  latter  itself  is  deeply  notched  dorsally  and  t^entraJly 
and  on  account  of  this  groove  quite  prominent  laterally.  It  is  thus  seen  that 
the  walls  of  the  bothria  are  comparatively  thin.  During  life  they  are  quite 
mobile,  as  might  be  concluded  from  their  general  appearance  as  weU  as  from 
their  anatomy.  Altho  the  greatest  dorsoventral  diameter  of  both  the  cavity 
and  the  walls  is  in  the  posterior  portion  of  the  bothrium,  the  more  functional 
portion  would  seem  to  be  the  anterior  part  immediately  behind  the  notch  of 
the  terminal  disc.  On  account  of  its  powerful  musculature  the  disc  evidently 
greatly  assists  the  relatively  thicker  walls  of  the  bothria  in  that  region  in 
forming  a  more  powerful  organ  of  adhesion  than  posteriorly.  The  thin  walls 
behind  would,  on  the  other  hand,  better  assist  the  sagittal  musculature  in 
maintaining  suction  by  presenting  a  greater  surface  internally  for  application 
to  the  mucosa  of  the  host's  intestme.  The  measurements  of  the  organ  are 
given  in  the  table  below. 

The  first  segments  are  subcuneate  in  outhne,  and  show  subdivision  in  a 
manner  similar  to  that  of  B.  scorpii.  Each  primary  segment  is  divided  into 
two  segments  of  the  second  order  (Fig.  24),  and  farther  back  these  in  turn  into 
segments  of  the  third  order,  and  so  on,  until  in  the  region  where  the  reproduc- 
tive rudiments  appear  the  primary  segment  contains  thirty-two  subsegments. 
This  plan  can  be  followed  as  in  B.  scorpii  even  into  the  region  of  differentiation, 
and  indeed  much  more  readily  since  there  is  much  less  irregularity  due  to  inter- 
calated segments  and  the  further  subdivision  of  others.  Furthermore,  the 
same  sort  of  dominance  of  the  anterior  end  of  the  primary,  secondary,  tertiary 
and  quaternary  segments — that  is,  imtil  a  group  of  four  reproductive  rudiments 
can  be  recognized — is  seen  not  only  in  the  size  of  the  subdivisions  but  especially 
in  the  first  portion  of  the  region  of  differentiation,  in  the  rate  of  differentiation 
of  the  common  rudiment  into  the  different  proximal  organs  of  the  reproductive 
system.  As  soon,  however,  as  the  lumina  of  the  uterus-sacs  appear,  the  plan 
becomes  obscured  by  the  gradual  enlargement  of  the  posterior  borders  of  the 
subsegments,  even  to  those  of  the  fifth  order.  Thus,  in  turn  there  may  be  seen 
defined,  as  one  follows  them  backward,  groupings  of  thirty-two,  sixteen,  eight, 
four  and  two  sets  of  genitalia.  Eventually,  at  the  posterior  end  of  medium 
sized  strobilas  and  for  considerable  stretches  of  the  largest  these  pairs  become 
separated,  so  that  the  segment  contains  only  one  set  of  reproductive  organs. 
These  hindermost  segments  are  usually  about  four  and  a  half  times  as  broad  as 
long,  but  in  the  most  relaxed  strobilas  they  may  be  only  twice  as  broad  as  long. 
The  ripe  segments  in  some  cases  may  be  so  much  elongated  and  constricted  at 
their  ends  that  they  appear  barrel-shaped.  This  accounts  for  the  apparent 
discrepancy  in  the  measurements  of  the  third  and  fourth  specimens  of  the  table 
below.  As  shown  (Figs.  25, 69)  the  anterior  part  of  the  strobila  has  a  dorsoven- 
tral diameter  almost  as  great  as  the  transverse  one — as  a  matter  of  fact  some 
parts  of  the  segments  are  here  almost  spherical  in  cross-section — while  the 


126 


ILLINOIS  BIOLOGICAL  MONOGRAPHS 


[414 


posterior  part  is  comparatively  thick  and  slightly  more  convex  ventrally  than 
dorsally.  The  strobila  as  a  whole  gradually  enlarges  from  the  former  to  the 
latter. 

The  following  table  gives  the  measurements  of  six  of  the  largest  specimens 
at  hand;  all  dimensions  are  given  in  millimeters. 


Length 

Maximuin  breadth 
Breadth  half  way 

along  the  strobila 
Same  immediately 

behind  scolex 
Length  of  scolex 
Width  posteriorly 
Width  of  terminal 

disc 
Depth  posterioriy 
Depth  of  terminal 

disc 
Length  of  first 
(primary)  seg- 
ment 
Breadth  of  same 

posteriorly 
Length  of  ripe  seg- 
ment 
Breadth  of  same 


178 

97 

66 

53 

48 

2.74 

1.67 

1.18 

0.72 

1.75 

2.04 

1.25 

0.80 

0.64 

0.55 

0.80 

0.26 

0.18 

0.18 

0.18 

3.35 

0.68 

1.38 

0.83 

1.11 

0.91 

0.26 

0.40 

0.24 

0.37 

1.37 

0.31 

0.42 

0.50 

0.44 

2.44 

0.27 

0.78 

0.38 

0.60 

1.16 

0.22 

0.18 

0.26 

0.30 

1.52 

0.15 

0.27? 

0.14 

0.31 

1.03 

0.22 

0.37? 

0.27 

0.33 

0.80 

0.87 

1.14 

1.30 

0.40 

2.74 

1.67 

0.80 

0.66 

0.51 

38 

1.77 

1.34 

0.18 
1.30 
0.37 

0.48 
0.71 

0.31 

0.26 

0.31 

0.61 
1.34 


The  cuticula  is  very  thin,  being  only  3.5/i  in  thickness,  and  with  the  highest 
magnifications  is  resolved  into  two  layers — an  outer  and  an  inner,  the  former 
about  one-half  the  thickness  of  the  latter,  and  separated  from  it  by  a  stratum 
of  granules  so  minute  a»  to  more  nearly  resemble  a  membrane.  The  outer 
surface  of  the  cuticula  is  provided  with  a  similar  membrane,  since  there  are  no 
cirri  or  pseudocilia  whatsoever.  A  distinct,  tho  very  thin  basement  mem- 
brane, is  also  to  be  seen.  The  two  strata  of  the  cuticula  seem  to  be  of  pretty 
much  the  same  consistency  since  they  stain  about  the  same,  altho  the  outer 
constantly  appears  somewhat  darker  at  first  sight  on  account  of  the  proximity 
of  its  two  bounding  membranes.  On  the  scolex  the  outer  layer  is  modified 
into  extremely  short  and  fine  spinelets,  which,  while  absent  from  the  terminal 
disc  as  well  as  the  posterior  borders  of  the  segments,  are  well  developed  in  the 
bothria  and  out  over  the  edges  of  its  walls. 

The  subcuticula  has  the  usual  reticular  appearance,  is  about  58/i  in  thick- 
ness and  is  provided  with  numerous  comparatively  large  nuclei  (5  to  7.5/z  in 
diameter)  distributed  equally  thruout  the  tissue,  excepting  for  a  stratum  about 
15m  in  thickness  immediately  beneath  the  cuticula,  which  is  almost  constantly 
free  of  them.    This  outer  layer  is,  of  course,  composed  of  the  processes  of  the 


415]  PSEUDOPHYLLIDEA  FROM  FISHES— COOPER  127 

syncitial  cells  below,  as  well  as  of  other  structures  lying  more  deeply  in  the 
parenchyma. 

The  parenchyma  shows  nothing  of  particular  interest  excepting  for  the  com- 
paratively large  nuclei  of  its  cells.  These  are  on  the  average  slightly  larger 
than  those  of  the  subcuticula,  the  largest  being  more  constantly  about  7.5^  in 
length.  No  distinct  traces  of  chalk-bodies  were  found  in  sectioned  material 
altho  numerous  branches  of  the  excretory  system  resemble  such  when  cut 
transversely. 

The  musculature  of  this  species  is  especially  well  developed.  The  frontal 
fibres,  altho  rather  small,  are  quite  numerous,  considerably  isolated  from  each 
other,  and  extend  from  the  layer  of  vitelline  glands  on  one  surface  to  that  on 
the  other,  everywhere  intermingUng  with  the  powerful  longitudinal  series  and 
being  discontinuous  only  where  the  largest  of  the  reproductive  organs  are 
situated.  This  applies,  however,  to  mature  proglottides,  for  in  the  segments 
immediately  behind  the  scolex  they  are  all  but  absent.  In  frontal  series  they 
are  seen  to  be  continuous  from  segment  to  segment  but  naturally  slightly  more 
numerous  between  the  sets  of  reproductive  organs,  altho  they  pass  freely 
among  the  testes.  The  same  description  applies  relatively  to  the  sagittal 
fibres.  Dorsoventrally  they  intermingle  with  the  vitelline  follicles.  On  the 
other  hand,  the  longitudinal  series  presents  quite  a  marked  difference.  As  a 
matter  of  fact  the  pronounced  development  of  these  fibres  seems  to  be  an  im- 
portant characteristic  of  the  species.  They  form  an  area  on  each  surface  in 
cross-section  about  125jli  in  thickness  and  consequently  so  wide  as  to  restrict 
the  cortical  and  medullary  portions  of  the  parenchyma  to  two  narrow  regions, 
respectively  about  75  and  90/x  in  thickness,  as  shown  in  figure  86.  The  indi- 
vidual fibres  are  large  (as  much  as  6.5ju  in  diameter),  not  united  into  groups  as  in 
B.  scorpii  and  continuous  as  a  whole  from  joint  to  joint.  On  account  of  their 
great  number  and  matted  appearance  in  frontal  or  sagittal  series  it  was  found 
impossible  to  determine  their  exact  length;  but  it  may  be  said  that  in  all 
probability  they  do  not  extend  individually  for  more  than  one  or  at  most  two 
sets  of  genitalia  along  the  strobila.  Only  a  weakly  developed  outer  longitudinal 
series  is  present,  altho  the  foremost  segments  have  prominent  posterior  borders, 
as  shown  in  figure  24.  What  might  at  first  glance  be  considered  as  such,  are 
the  very  large  and  numerous  longitudinal  cuticular  fibres  forming  a  compara- 
tively wide  area  outside  of  the  subcuticular  nuclei  in  the  anterior  end  of  the 
strobila  (Fig.  69). 

As  might  be  expected  from  the  external  appearance  of  the  structure  the 
musculature  of  the  scolex  is  well  developed.  Powerful  sagittal  and  radial 
fibres  pass  for  a  short  distance  behind  the  terminal  disc,  which  region  is  there- 
fore, as  noted  above,  the  most  functional  portion  of  the  bothrium.  At  the 
middle  of  the  scolex,  however,  only  the  sagittal  series  is  very  prominent,  while 
posteriorly  at  the  thickest  part  of  the  organ,  these  too  disappear  almost  entirely. 
The  same  diminution  of  the  coronal  series  from  in  front  backwarks  is  to  be  seen, 
although  they  are  at  no  level  nearly  so  prominent  as  the  other  two  sets.  As  in 
the  strobila  the  longitudinal  fibres  are  very  numerous.    They  pass  uninter- 


128  ILLINOIS  BIOLOGICAL  MONOGRAPHS  [416 

ruptedly  into  the  base  of  the  scolex  as  two  narrow  and  very  thick,  dorso- 
ventral  bundles,  somewhat  trapezoidal  in  cross-section,  and  attach  for  the  most 
part  as  far  forward  as  the  terminal  disc  to  the  walls  of  the  bothria  in  the  usual 
oblique  manner.  Only  a  very  few  pass  on  to  the  tip  of  the  scolex.  As  might 
be  gathered  from  the  prominence  of  the  edges  of  the  terminal  disc,  its  longi- 
tudinal arcuate  fibres  are  also  very  well  developed,  and  obviously  essentially 
related  to  the  greater  power  of  adhesion  of  the  anterior  part  of  the  bothrium 
on  each  face  of  the  scolex. 

The  nervous  system  consists  of  two  chief  strands,  from  30  to  35^  in  dia- 
meter, passing  thruout  the  strobila  at  the  junctions  of  the  lateral  three-four- 
teenths with  the  median  four-sevenths  of  its  transverse  diameter.  These 
proportions  are,  however,  in  other  parts  of  the  strobila  (especially  anteriorly)^ 
or  in  different  strobilae,  depending  on  the  degree  of  contraction,  often  more 
nearly  1:3:1.  They  are  moreover  usually  nearer  the  dorsal  surface  of  the 
medulla  than  the  ventral.  This  is  on  account  of  the  fact  that  their  course 
is  much  interfered  with  by  the  testes,  both  having  only  a  limited  space 
in  which  to  accommodate  themselves.  They  pass  into  the  scolex  close  to- 
gether— their  axes  actually  about  70/i  apart — and  then  very  gradually  diverge,, 
only  to  start  to  converge  again  about  two-fifths  of  the  length  of  the  scolex  from 
its  tip.  After  diminishing  very  sUghtly  in  diameter  each  enlarges  into  an 
anteriorly  truncated  ganglion,  united  with  its  fellow  of  the  other  side  by  a 
single  commissure  which  is  bent  sUghtly  forward  into  the  tip  of  the  terminal 
disc.  The  anterolateral  edges  of  the  ganglia  are  at  once  spUt  into  two  com- 
paratively large  nerves  which  pass  out  directly  to  the  edges  of  the  disc  and  at 
right  angles  to  the  longitudinal  axes  of  the  chief  strands.  This  arrangement 
gives  these  anterior  connections  of  the  nerve  strands  a  very  characteristic 
appearance  both  in  transverse  and  frontal  sections.  • 

The  main  longitudinal  channels  of  the  excretory  system  are  at  least  four 
in  number,  only  two  of  which,  however,  are  at  all  constant  in  course,  if  not  in 
size.  These  occupy  a  ventral  position  thruout  the  strobila,  while  the  remaining 
vessels,  two  or  more  in  number  and  connected  by  numerous  and  irregular 
branches,  are  more  dorsal  in  position.  In  the  foremost  segments  the  ventral 
vessels  are  comparatively  close  together  and  situated  considerably  within  the 
nerve  strands,  i.e.,  towards  the  median  line  (Fig.  69).  There  they  vary  from 
13  to  15/i  in  diameter,  the  dorsal  vessels  having  diameters  as  much  as  18/*. 
As  all  of  these  main  vessels  pass  backwards  in  the  strobila  they  diverge  con- 
siderably, and  become  more  and  more  irregular  in  course  as  the  reproductive 
rudiments  are  neared.  The  ventral  vessels,  however,  remain  more  constant 
in  course.  In  the  anterior  part  of  the  proglottis  they  pass  just  outside  of  the 
vas  deferens  on  one  side  and  the  uterine  duct  on  the  other,  while  in  the  posterior 
region  of  the  genital  segment  they  skirt  the  edges  of  the  ovary  or  in  many  cases 
pass  beneath  them.  They  may  attain  a  diameter  of  40/x.  Furthermore,  while 
the  dorsal  vessels  are  forming  a  very  open  plexus  by  nimierous  large  transverse 
connections  in  the  lateral  portions  of  the  medulla,  the  ventral  pair  give  off  at 
right  angles  to  their  courses  many  short  lateral  branches  passing  among  the 


417]  PSEUDOPHYLLIDEA  FROM  FISHES— COOPER  129 

testes  and  other  median  connections  more  numerous  between  the  sets  of  repro- 
ductive rudiments.  In  mature  proglottides  only  the  more  regular  ventral 
vessels  can  be  followed  with  any  degree  of  satisfaction.  As  the  vessels  enter 
the  scolex,  the  dorsal  series  soon  breaks  up  into  an  irregular  plexus,  consisting 
of  large  branches  and  lacunae,  situated  more  particularly  in  the  large  posterior 
portions  of  the  organ;  while  the  ventral  pair  quickly  diminish  in  size  and 
regularity  of  course,  but  do  not  lose  their  identity  entirely  until  at  least  one-half 
the  length  of  the  bothria  is  passed.  In  the  youngest  strobilas  at  hand  what 
was  considered  to  be  the  "end  proglottis"  showed  the  excretory  system  as 
terminating  in  an  irregular  plexus  from  which  numerous  foramina  secundaria 
passed  to  the  exterior  quite  as  in  Fraipont's  (1881,  Fig.  8,  Pi.  II)  view  of 
the  conditions  in  B.  scorpii. 

The  genitalia  have  the  general  habit  of  the  genus.  The  common  genital 
opening  or  cloaca,  situated  dorsally  in  the  median  line,  is  usually  about  half 
way  between  the  anterior  and  posterior  borders  of  the  proglottis,  while  the 
uterus  opening  on  the  ventral  surface  is  quite  near  the  anterior  border,  so  close 
in  fact  that  in  much  contracted  strobilas  it  may  be  all  but  obscured  by  the 
posterior  border  of  the  proglottis  ahead.  Unlike  B.  scorpii  both  openings 
are  situated  at  the  bottom  of  comparatively  deep  depressions,  as  shown  in 
figure  102,  that  of  the  genital  cloaca  being  usually  circular  in  outline,  about  0.10 
mm.  in  diameter  and  0.11  in  depth.  In  some  proglottides,  however,  it  may  be 
so  contracted  longitudinally  as  to  present  a  transverse  diameter  of  0.45inm., 
with  a  length  of  only  0.04  and  a  depth  of  0.13.  The  ductus  hermaphroditicus 
or  secondary  cloaca  is  very  shallow  in  this  species,  and  only  about  55/x  in  dia- 
meter. In  most  of  the  preparations  made  it  was  usually  occupied  by  the  tip 
of  the  cirrus,  when  the  latter  was  not  extruded,  the  opening  of  the  vagina  form- 
ing a  very  narrow  crescent-shaped  sUt  close  behind  it.  In  some  cases,  how- 
ever, both  the  cloaca  and  the  ductus  were  so  contracted  longitudinally  that 
the  tip  of  the  cirrus  was  found  almost  inserted  into  the  entrance  to  the  vagina. 
From  this  fact,  together  with  the  comparatively  great  depth  of  the  cloaca  in 
such  states  of  contraction,  it  is  conceivable  that  self-impregnation  may  take 
place;  but  nothing  in  the  nature  of  a  cloacal  sphincter  to  assist  in  this  function 
is  present. 

The  testes  are  continuous  from  proglottis  to  proglottis  in  two  lateral  fields 
separated  by  the  median  row  of  proximal  organs  of  the  reproductive  system. 
Since  dorsoventrally  they  occupy  almost  the  whole  diameter  of  the  medulla, 
each  is  further  separated  into  two  more  or  less  irregular  fields  by  the  nerve 
strand.  The  more  median  field  consists  of  little  more  than  one  longitudinal 
row  of  the  follicles.  The  number  of  testes  is  usually  from  25  to  30  on  each  side, 
with  a  variation  of  a  few  in  either  direction,  thus  making  the  total  niunber 
from  50  to  60  on  the  average.  They  are  ellipsoidal  in  shape  with  their  longest 
axes  transverse  to  that  of  the  strobila,  and  attain  dimensions  of  0.1 10mm.  in 
width  (in  the  transverse  direction),  0.060  in  length  and  0.080  in  depth.  On 
accoimt  of  their  large  size,  as  compared  with  that  of  B.  scorpii,  they  are  natural- 
ly much  more  regularly  arranged  in  the  proglottis. 


130  ILLINOIS  BIOLOGICAL  MONOGRAPHS  [418 

The  vas  deferens  fonns  a  very  compact  mass  of  coils  lateral  to  the  cirrus- 
sac  and  extending  from  the  utenis-sac  ahead  to  the  wing  of  the  ovary  on  that 
side  behind.    It  alternates  irregularly  from  right  to  left,  as  does  the  greater 
part  of  the  uterine  tube  which  occupies  a  similar  position  on  the  other  side  of 
the  cirrus-sac.    In  states  of  moderate  contraction  of  the  proglottis  it  is  about 
0.22imn.  in  length,  0.16  in  width  and  0.18  m  depth.    Inmiediately  within  the 
cirrus-sac  the  vas  deferens  continues  as  a  thin-walled  senainal  reservoir,  sUghtly 
coiled  and  occupying  approximately  the  ventral  one-third  of  the  former.    It 
varies  from  35  to  80/x  in  diameta:,  but  in  the  sections  made  it  was  found  to 
contain  only  a  comparatively  small  number  of  spermatozoa.    Beyond  this 
receptacle  the  duct  narrows  down  to  about  5/i  in  diameter  and  continues  as 
the  ductus  ejaculatorius  with  many  coils,  situated  in  the  proximal  one-third 
of  the  sac  alongside  the  seminal  reservoir  even  when  the  cirrus  is  protruded. 
This  portion  of  the  duct  very  graduaUy  enlarges  as  its  circular  muscle  fibres 
become  more  numerous  and  its  lining  thicker  and  thicker  as  it  merges  into  the 
cuticula  of  the  cirrus  proper.    The  latter  is  about  5m  in  thickness  and  deeply 
"cleft,"  or,  to  be  more  precise,  broken  up  into  a  great  nimiber  of  coral -like 
villi  by  means  of  irregular  i  eparate  pittings  reaching  almost  to  the  base  of  the 
tissue.    The  duct  may  here  (at  the  middle  of  the  cirrus-sac)  attain  a  diameter 
of  2Sn.    The  cirrus  proper  is  somewhat  conical  when  protruded  (Fig.  102)  and 
has  a  TnaTiTniim  length  and  width  of  130  and  85m,  respectively.    However,  on 
account  of  the  similar  structxire  and  large  diameter  (25/*)  of  that  part  of  the 
duct  still  invaginated  \sithin  the  sac  one  is  led  to  think  that  the  organ  may 
reach  a  much  greater  length — ^with  probably  a  considerably  smaller  diameter. 
From  the  tip  of  the  cirrus  to  the  inner  end  of  its  duct,  where  the  cleft  cuticula 
stops  and  which  point  might  well  be  the  f  imctional  tip  of  the  organ,  it  is  at  least 
0.28mm.  in  length.    Thus  it  would  seem  that  the  organ  functions  as  a  very 
eflScient  and  powerful  intromittent  organ.    The  cirrus-sac  is  ovoid  in  shape  and 
comparatively  large,  being  about  250^  in  depth  (length  of  longitudinal  axis, 
which  is  directed  dorsoventrally),  180^  in  length  and  210  in  width,  when  the 
cirrus  is  not  protruded,  and  thus  somewhat  flattened  in  the  longitudinal  axis 
of  the  strobila.    Its  wall  is  only  about  2.5m  hi  thickness,  and  composed  of  very 
fine  muscular  fibres  the  direction  of  which  was  not  determined  with  certainty. 
The  contents  of  the  sac  consists  of  a  loose  parenchymatous  tissue,  containing 
many  nuclei  and  numerous  retractor  muscle  fibres.    The  nuclei,  which  are 
situated  close  around  the  duct  and  are  comparatively  nimierous,  are  in  all 
probability  myoblastic  in  their  nature.    The  retractor  fibres  pass  obUquely 
upwards  and  inwards  from  all  points  of  the  wall  to  their  points  of  attachment 
to  the  cuticula  of  the  cirrus.    This  attachment  is  seen  very  nicely  when  the 
cirrus  is  protruded  (Fig.  102),  for  then  the  fibres  are  much  elongated  and  theycan 
be  followed  even  to  the  evaginated  cuticula.    Their  myoblastic  nuclei  are  quite 
easily  distinguished,  especially  in  the  everted  portion  of  the  cirrus.    The  cirrus- 
sacs  are  all  in  the  median  line,  their  longitudinal  axes  being  almost  constantly 
in  the  median  sagittal  plane. 


419]  PSEU DOPEY LUDEA  FROM  FISHES— COOPER  131 

The  vagina  opens  immediately  behind  the  cirrus  at  the  bottom  of  the 
genital  cloaca  with  an  aperture  which  forms  an  arc  of  a  circle.  It  passes  ven- 
trally  in  the  median  line  close  to  the  posterior  wall  of  the  cirrus-sac  and  then, 
after  taking  a  few  coils  on  a  level  with  the  lower  border  of  the  isthmus,  it  joins 
the  oviduct  a  short  distance  from  the  origin  of  the  latter.  Thruout  its  course 
it  is  considerably  flattened  anteroposteriorly,  its  dimensions  being  alongside 
the  cirrus-sac  about  46  by  IS/x.  It  is  provided  with  a  cuticula,  3m  in  thickness 
and  thrown  into  longitudinal  folds.  It  gradually  diminishes  in  size  until  a 
diameter  of  about  15/*  is  reached — at  the  ventral  border  of  the  ovary — ^and 
then  enlarges  somev;hat  before  joining  the  oviduct  in  a  dorsoventral  transverse 
plane,  but  without  forming  a  distinct  receptaculum  seminis,  altho  a  consider- 
able length  of  this  portion  of  the  duct  is  often  found  filled  with  spermatozoa. 
UnUke  that  of  B.  scorpii  the  ovary  of  this  species  is  a  compact  organ,  0.60mm. 
wide,  0.10  long  (the  wings)  and  0.13  deep.  The  elongated  oval  shaped  wings 
(Fig.  86),  usually  directed  forwards,  since  the  whole  organ  is  situated  right 
at  the  posterior  border  of  the  proglottis  and  close  against  the  \iterus-sac  of  the 
next  proglottis,  are  attached  by  narrow  necks  to  the  somewhat  wider  and  bul- 
bous isthmus.  Ova  from  the  latter  are  oval  in  shape,  measure  about  15  by  12/i 
and  have  nuclei  6/i  in  diameter  with  nucleoli  2.5^.  As  in  B.  scorpii  the  wings 
occupy  the  whole  of  the  dorsoventral  diameter  of  the  medulla,  while  the  median 
bulbous  portion  of  the  isthmus  almost  reaches  the  same  level  dorsally.  The 
oviduct  arises  dorsolaterally  from  the  isthmus  in  the  somewhat  elongated 
oocapt  which  has  a  diameter  of  20  to  25/i  and  a  length  of  from  25  to  30/Lt.  Im- 
mediately beyond  the  oocapt  it  gradually  enlarges  from  a  diameter  of  7  to  20^ 
where  it  is  joined  by  the  vagina  only  a  short  distance  either  to  the  right  or 
left  from  its  point  of  origin.  At  the  junction  of  these  two  ducts  there  is  only 
a  very  small  vestibule,  as  in  the  foregoing  species,  into  which,  nevertheless, 
the  oviduct  may  be  seen  to  open  by  a  longitudinal  slit,  and  from  one  comer 
of  which  it  proceeds  with  a  diameter  of  6.5/i.  After  continuing  almost  directly 
dorsally  with  only  a  few  very  open  coils  it  is  joined  at  about  the  level  of  the 
upper  edge  of  the  isthmus  by  the  common  vitelline  duct.  Thruout  its  coiu^e 
the  epithelium  of  the  oviduct  is  poorly  provided  with  cilia  and  is  surrounded 
by  only  a  comparatively  small  number  of  circular  muscle  fibres.  The  common 
vitelline  duct  has  a  diameter  just  beyond  its  point  of  origin  with  the  oviduct  of 
25/i  or  more.  It  is  directed  transversely  above  the  generative  space  from  the 
dorsal  edge  of  one  horn  of  the  ovary  to  about  the  median  line,  where  the  separate 
vitelline  ducts  unite.  In  sections  it  is  usually  filled  with  yolk  cells.  The  vitel- 
line ducts,  themselves,  pass  laterally  close  in  front  of  the  wings  of  the  ovary, 
and  hence  between  them  and  the  vas  deferens  and  uterine  tube.  When  empty, 
they  have  a  minimum  diameter  of  only  Zti.  The  vitelline  follicles,  as  shown  in 
figure  86,  occupy  almost  the  whole  of  the  cortical  parenchyma  between  the 
longitudinal  muscles  and  the  nuclei  of  the  subcuticular  cells.  They  are  ellip)- 
soidal  in  shape,  their  longest  diameters  being  directed  at  right  angles  to  the 
surface  of  the  strobilia.  They  are  longest  near  the  median  line  and  smallest 
at  the  edges  of  the  strobila.    In  general  they  may  be  said  to  be  arranged  in  two 


132  ILLINOIS  BIOLOGICAL  MONOGRAPHS  [420 

lateral  fields  continuous  from  proglottis  to  proglottis,  but  the  latter  are  united 
dorsally  and  ventrally  between  the  sets  of  genitalia  by  the  largest  which  are 
somewhat  more  numerous  and  irregularly  arranged  ventrally.  The  average 
maximum  depth,  width  and  length,  of  the  individual  follicles  are  70,  50,  and 
45/i,  respectively,  while  the  diameter  of  the  smallest  lateral  follicles,  more 
nearly  spherical  in  shape,  is  about  25/x.  Their  number  as  calculated  from  sec- 
tions averages  from  800  to  1000  for  each  set  of  reproductive  organs.  The 
shell-gland  is  situated  dorsally  and  to  one  side  of  the  median  line,  the  beginning 
of  the  uterine  tube  occup>ing  the  other  side  of  the  generative  space.  The  latter 
is  here  not  so  much  a  space  enclosed  by  the  ovaries  as  the  region  of  union  of  the 
proximal  portions  of  the  generative  ducts.  That  part  of  the  oviduct  with  which 
the  cells  of  the  gland  are  connected  is  only  about  60/i  in  length.  Beyond  the 
Gotype  the  oviduct  gradually  enlarges  as  it  passes  to  the  other  side  to  become  the 
uterine  tube.  Farther  ventrally  the  comparatively  large  coils  of  the  uterine 
duct  pass  back  to  the  same  side  again  and  occupy  a  space  lateral  to  the  cirrus- 
sac,  as  mentioned  above  in  connection  with  the  vas  deferens.  Just  beyond  the 
shell-gland,  where  the  syncitial  nature  of  its  epithelium  can  be  made  out,  the 
oviduct  has  a  diameter  of  13/x.  The  uterus-sac  is  relatively  large  in  this 
species,  spherical  in  shape  and  occupies  one-third  of  the  diameter  of  the  proglot- 
tis anteroposteriorly  as  well  as  laterally.  This  applies  to  proglottides  in  mod- 
erate state  of  contraction,  for  in  much  relaxed  ones  it  is  somewhat  elUpsoidal 
in  shape  with  its  long  axis  in  the  median  line.  The  youngest  uterus-sac  which 
was  seen  to  contain  eggs  in  the  largest  and  most  relaxed  strobila  at  hand  was 
spherical  and  had  a  diameter  of  0.15mm.,  while  the  largest  of  the  same  chain, 
also  spherical,  was  0.50mm.  in  diameter.  But  even  when  they  appear  circular 
in  outline  from  a  superficial  view,  they  are  not  in  reality  spherical  since  they 
lead  off  funnel-wise  ventrally  to  the  uterus-opening.  The  superficial  aspects 
of  the  latter  have  been  already  dealt  with  above,  so  that  it  will  be  necessary  to 
state  here  only  that  it  has  quite  the  same  structure  as  that  of  B.  scorpii,  and 
that  the  actual  aperture  when  formed  is  irregularly  circular  in  outline  with  a 
transverse  diameter  of  60  to  85/i.  The  wall  of  the  uterus-sac  just  within- the 
opening  is  in  many  cases  broken  up  into  numerous  processes,  evidently  cuti- 
cular  in  their  nature,  which  protrude  thru  the  aperture. 

The  egg  is  ellipsoidal  in  shape  during  life,  and  from  62  to  66)ix  long  by  42  to 
45/i  wide.  None  were  found  to  contain  oncospheres,  but  only  masses  of  cells 
such  as  shown  in  figures  106  and  107,  the  smaller  of  which  obviously  represents 
an  earlier  stage  in  the  division  of  the  latter.  While  most  of  these  cells  are  yolk- 
cells,  the  large  one  shown  at  one  end  of  figure  106  is  the  undivided  egg.  The 
granules  of  figure  107  are  those  resulting  from  the  breaking  down  of  the  yolk- 
cells.  Eggs  sectioned  in  the  uterus-sac  showed  similar  stages  in  development 
and  confirmed  these  statements.  These  measurements  and  drawings  were 
made  on  August  2,  1912,  so  that  it  is  probable  that  the  development  of  the 
oncosphere  is  completed  in  autumn. 

Concerning  the  life-history  of  this  species  it  may  be  said  that  many  of  the 
earliest  formed  segments  are  lost  long  before  they  become  sexually  mature, 


421]  PSEUDOPHYLLIDEA  FROM  FISHES— COOPER  133 

since  most  of  the  youngest  strobilas  were  found  lacking  the  end  proglottis. 
Constrictions  at  about  the  middle  were  present  in  many  of  them,  as  if  the  length 
of  segments  behind  that  region  might  be  thrown  off  as  a  whole.  Since,  however, 
this  is  not  a  constant  feature,  it  is  considered  to  be  due  rather  to  the  fixation  of 
a  wave  of  contraction  passing  over  the  strobila,  such  as  may  be  seen  in  living 
individuals  as  well  as  in  plerocercoids  of  other  genera  of  cestodes,  e.g., 
Scolex  polymorphus. 

From  the  foregoing  description  it  is  to  be  seen  that  this  species  of  cestode  is 
new.  The  specific  name,  here  chosen,  has  reference  to  the  peculiar  shape  of 
the  scolex  as  seen  from  the  side:  cuspis,  an  arrow-head. 

The  material  studied  consisted  of  Nos.  N.B.  6a,  N.B.  6d,  N.B.  6g,  No.  47, 
No.  50a,  No.  54c  and  P.B.  2  from  Stizosiedion  vitreum,  N.B.  38a,  08107,  08108, 
08109  and  08110  from  Stizostedion  canadense,  and  Ha  34a  and  Ha  35a  from 
Hiodon  tergisus,  in  the  collection  of  the  University  of  Illinois;  Nos.  398,  423 
and  481  from  S.  vitreum  in  the  collection  of  Dr.  H.  J.  Van  Cleave;  Nos.  7b  from 
Percina  caprodes  and  421  from  a  "Pickerel"  in  the  collection  of  Dr.  G.  R. 
LaRue;  twelve  toto  preparations  from  Perca  fiavescens  in  Dr.  A.  S.  Pearse's 
collection;  and  Nos.  41,  170,  172,  173,  174,  193  and  194  from  S.  vitreum  in  the 
writer's  collection.  The  material  from  Perca  fiavescens  was  larval,  while  that 
from  Percina  caprodes  was  mature  but  of  a  small  size. 

BOTHRIOCEPHALUS  MANUBRIFORMIS  (Linton  1889) 
[Figs.  26,  27,  62,  73,  87,  88,  97] 


1889 

Dibothrium  manubriforme 

Linton 

1889 

-.456 

1890 

Dibothrium  manubriforme 

Linton 

1890 

:728 

1898 

Dibothrium  laciniatum 

Linton 

1898  : 

:42S 

1898 

Dibothrium  manubriforme 

Linton 

1898 

:429 

1899 

Botkriocephalus  laciniatua 

Liihe 

1899 

:43 

1900 

Bothriocephalus  manubriformis 

Ariola 

1900  ; 

:410 

1901 

Dibrotkrium  laciniatum 

Linton 

1901a 

:437 

1901 

Bothriocephalus  kistiophorus 

Shipley 

1901  ; 

;209 

1902 

Bothriocephalus  manubriformis 

Porona 

1902  ; 

:7 

Specific  diagnosis:  With  the  characters  of  the  genus.  Large  cestodes  up 
to  220mm.  in  length  by  5mm.  in  maximum  breadth.  Scolex  large,  elongate, 
with  prominent  terminal  disc  deeply  notched  laterally  as  well  as  surficially, 
constricted  posteriorly;  length  2  to  3.5mm.,  depth  at  middle,  1.0,  breadth  of 
disc,  1.0.  Bothria  long  and  very  narrow  posteriorly  where  the  walls  are  quite 
thick.  First  segments  cuneate  with  salient  posterior  borders  which  are  dis- 
tinctly emarginate;  middle,  broadly  cuneate,  less  emarginate;  posterior  or 
mature,  many  times  broader  than  long  and  closely  crowded,  5  by  0.2mm.; 
gravid  proglottides,  2  by  0.4mm.  Posterior  half  to  two-thirds  of  the  strobila 
provided  with  a  median  line  (the  combined  uterus-sacs). 

Cuticula  4.5jLt  thick.  Calcareous  bodies  large,  18  to  26  by  11  to  15/i. 
Longitudinal  muscles  well  developed,  in  bundles.  Anteriorly  four  chief  ex- 
cretory vessels. 


134 


ILLINOIS  BIOLOGICAL  MONOGRAPHS 


[422 


Genital  cloaca  median  or  slightly  displaced  towards  either  side,  deep  and 
narrow,  separated  from  hermophroditic  duct  by  a  narrow  velum,  half  way 
between  anterior  and  posterior  borders  of  the  proglottis.  Vagina  opens  im- 
mediately behind  cirrus  or  very  slightly  to  one  side. 

Testes  ellipsoidal  in  shape,  64  to  75/i  wide,  45  to  60  long,  64  to  80  deep; 
60  to  70  in  number,  dorsal  in  the  medulla.  Vas  deferens  closely  applied  to 
inner  end  of  cirrus  pouch,  85ju  long,  175  wide  and  400  thick,  somewhat  crescen- 
tic  in  the  dorsoventral-transverse  plane,  opposite  the  uterus-sac.  Cirrus-sac 
long  and  cyhndrical,  0.50  by  0.14mm.,  inner  half  deflected  towards  the  vas 
deferens,  walls  very  thick,  composed  mostly  of  circular  muscles.  Cirrus  short, 
usually  not  extending  outside  of  the  proglottis,  30  to  35/i  in  diameter. 

Vagina  with  bulbous  sphincter  near  its  opening,  50/i  long  by  70  in  diameter. 
Ovary  irregularly  branched  but  compressed  anteroposteriorly,  0.45mm.  wdde; 
isthmus  only  ventral.  Oocapt  30)li  in  diameter.  Vitelline  follicles  extremely 
numerous,  35ai  long,  60  wide  and  85  thick.  Vitelline  reservoir  large,  60jLt  in 
diameter.  Uterine  duct  voluminous  on  both  sides  of  the  median  line,  crowding 
all  other  organs.  Uterus-sacs  alternate  irregularly  from  side  to  side,  each 
0.45mm.  in  diameter,  encroach  greatly  on  neighboring  segments,  with  thick 
musculo-glandular  funnel-shaped  ventral  portion.  Apertures  form  two  lines 
on  the  ventral  surface  1mm.  apart. 

Eggs  58  by  34/i,  dark  brown,  showing  thru  walls  ofuterus-sacs. 

Habitat:  Intestine  of  the  host. 


HOST 

LOCALITY 

COLLECTOR 

AUTHORITY 

Tetrapterm  alhidus 

Woods  Hole, 

Linton 

Linton 

1889  :  458 

(type  host) 

Mass. 

Eistiophorus  gladius 

Newport,  R.  I. 

Linton 

Linton 

1890  :  731 

Tarpon  atlantlcus 

U.  S.  N.  M. 
Woods  Hole, 

Linton 
Linton 

1898  :  435 

Istiophorus  nigricans 

Linton 

1901  :  448 

{  =  H.  gladius) 

Mass. 

Tetrapterus  imperator 

Woods  Hole, 

Linton 

Linton 

1901  :  447 

{  =  T.  albidtis) 

Mass. 

Eistiophorus  sp. 

Indian  and 
Pacific  oceans 

A.  Willey 

Shipley 

1901  :209 

Tetrapterus  belone 

Portoferrajo,  Id. 
Elba 

Damiani 

Parona 

1902  :7 

Type  specimen:  No.  4711,  Coll.  U.  S.  National  Museum. 
Co-type:  No.  16.461,  Collection  of  the  University  of  Illinois. 
Type  locality:  " Penekese? " 


Although  this  species  was  first  described  more  or  less  in  detail  by  Linton 
(1889:456)  and  further  notes  were  added  by  the  same  worker  in  the  following 
year  (1890:728),  the  writer  feels  that  there  is  still  much  to  be  learned  about  it 
in  spite  of  the  fact  that  Ariola  (1900:410)  was  able  to  indicate  the  genus  to 
which  it  belongs  and  to  correct  some  errors  concerning  the  arrangement  of  the 


423]  PSEVDOPHYLLIDEA  FROM  FISHES— COOPER  135 

bothria  in  his  rather  brief  description,  which  is  inadequate  for  diagnostic  pur- 
poses. Consequently  an  attempt  is  here  made  to  better  define  the  species  so 
far  as  can  be  done  with  the  poorly  preserved  alcoholic  material  referred  to 
immediately  above. 

In  general  appearance  the  worm  arrests  attention  on  account  of  the  very 
closely  arranged  posterior  genital  segments,  which  give  that  part  of  the  stro- 
bila  a  transversely  plicate  aspect.  On  closer  view  the  anterior  segments  with 
their  "salient"  posterior  borders  and  the  characteristic  scolex  are  seen  (Figs. 
26, 62) .    The  latter  was  described  by  Linton  as  follows : 

"Head  cuneate,  tetrangular,  truncate  in  front,  tapering  posteriorly  into 
a  cylindrical  neck-like  part  near  posterior,  then  expanding  so  that  the  posterior 
end  of  the  head  resem.bles  one  of  the  anterior  segments  of  the  body.  The 
general  appearance  of  the  head  when  viewed  laterally  [surficially]  is  there- 
fore somewhat  like  a  ball-bat,  the  constricted  part  representing  the  handle. 
Two  longitudinal  fossae  [bothria],  laterally  placed,  extend  from  the  anterior 
part  of  the  head  to  the  constricted  part.  Each  of  the  marginal  lobes  thus 
formed  is  indented  at  the  anterior  extremity  by  a  short  but  deep  [only  in 
much  contracted  material]  secondary  fossa,  which  together  with  the  two  lateral 
fossae,  give  the  head  when  viewed  in  front  a  four-lobed  appearance.  The  edges 
of  the  lobes  bordering  the  lateral  fossae  [the  walls  of  the  bothria]  are  thin- 
lipped  and  flexible;  anteriorly  there  is  a  transverse  elevation  forming  both  a 
lateral  and  a  marginal  rim  and  making  an  obtuse  angle  between  the  front  and 
the  side  of  the  head. "  This  is  the  pyramidal  or  somewhat  conical  terminal 
disc,  so  characteristic  of  the  scolex.  (Figs.  26,  27) .  The  walls  of  the  bothria  are 
"thin-lipped  and  flexible"  only  when  protruded  considerably;  in  moderate 
states  of  contraction,  that  is,  nearest  to  what  the  WTiter  considered  to  be  the 
probable  state  of  rest,  they  are  comparatively  thick  and  especially  so  in  the 
posterior  half  of  the  scolex  where  in  consequence  the  bothrium  is  reduced  to 
a  narrow  vertical  slit.  "  The  marginal  lobes,  when  at  rest,  have  a  roimded 
outline,  fullest  in  the  middle,  tapering  posteriorly,  appressed  slightly  anteri- 
orly, and  raised  into  two  small  eminences  on  each  side  of  the  secondary  fossae. 
The  head  in  a  marginal  view  is  somewhat  flask-shaped.  Seen  from  the  front 
the  head  is  squarish,  with  the  angles  rounded  and  the  sides  deeply  cleft,  the 
clefts  rounded,  the  lateral  clefts  deeper  than  the  marginal. " 

As  regards  the  segments  Linton  in  continuation  stated  that:  " Immediately 
back  of  the  head  the  segments  are  very  narrow,  and  for  a  greater  or  less  dis- 
tance, depending  on  the  state  of  contraction,  maintain  about  the  same  width 
as  the  base  of  the  head.  In  some  individuals  the  small  anterior  segments  con- 
tinue much  farther  back  from  the  head  than  in  the  one  figured.  The  segments 
are  alternately  short  and  long.  This  characteristic  is  quite  plainly  marked 
in  the  segments  which  immediately  foUow  the  head,  is  still  noticeable  on  the 
median  segments  and  also  on  the  posterior  ones,  but  is  not  so  plainly  marked 
on  the  latter  as  on  the  two  former. "  This  is  due  to  the  manner  of  subdirision 
of  the  segments  which  is  carried  out  in  the  same  way  as  in  B.  scorpii  and  B. 
cuspidatus.    It  can  be  followed  with  certainty,  however,  only  in  the  "  anterior" 


136  ILLINOIS  BIOLOGICAL  MONOGRAPHS  [424 

and  middle  portions  of  the  strobila  and  not  posteriorly  where  the  segments 
are  very  short  and  crowded  close  together  longitudinally,  even  tho  the  latter 
may  not  show  the  rudiments  of  the  reproductive  organs.  Figure  62  is  an 
outline  of  a  primary  segment,  the  fifth  from  the  scolex  in  this  case,  to  show 
this  method  of  subdivision.  Dominance  of  the  anterior  over  the  posterior 
half  of  the  segment  as  regards  rate  of  division  is  well  shown;  and  this  is  seen 
to  be  applicable  also  to  the  subsegments  even  to  those  of  the  fourth  order. 
''In  one  specimen  exaniined,"  to  continue  to  quote  from  Linton,  "the  first 
six  segments  did  not  show  this  alternation  in  size.  In  the  next  fourteen  seg- 
ments, however,  the  alternation  was  quite  evident. "  This  indicates  that  he 
noted  the  division  of  the  segments  into  subsegments  but  did  not  ascertain  the 
exact  manner  in  which  it  is  carried  out.  "The  small  anterior  segments  are 
terete,  subtriangular  in  outline,  narrow  in  front,  wide  behind,  the  length 
nearly  equal  to  the  greatest  breadth. "  It  is  rather  difficult  to  say  to  what 
segments  or  subsegments  the  latter  part  of  this  statement  refers,  since  it 
describes  not  only  what  is  here  considered  to  be  the  first  primary  segment, 
i.e.,  the  largest  segment  immediately  behind  the  scolex  as  shown  in  the  figure 
26,  but  also  many  of  the  major  subsegments  of  the  following  primary  segments 
— not  all,  however,  since  as  indicated  in  figure  62,  the  dominance  in  division 
mentioned  above  renders  subsegments  of  the  same  developmental  value  different 
in  size.  Furthermore,  as  regards  these  anterior  segments  it  must  be  empha- 
sized that  their  prominent  or  salient  posterior  borders  are  distinctly  emarginate, 
which  condition,  very  obvious  in  the  segments  immediately  behind  the  scolex, 
can  be  followed  back  to  the  region  where  the  segments  get  very  broad  and 
short.  Concerning  this  notching  of  the  posterior  border,  Linton  (1889:458) 
said:  "The  segments  of  the  first  series  are  sometimes  notched  or  crenulated 
on  the  posterolateral  margin,  with  a  single  median  indentation;  in  others  the 
edge  is  but  slightly  wavy;  in  others  it  is  nearly  entire. "  In  the  material  at  hand, 
however,  this  emargination  was  found  as  just  described  in  all  of  the  specimens, 
altho  in  much  contracted  strobilae  it  is  at  first  sight  apparently  absent.  ' '  The 
succeedihg  segments  are  much  broader  than  long.  At  the  widest  part  the 
ratio  of  the  breadth  to  the  length  is  as  much  as  fourteen  to  one.  As  the  seg- 
ments increase  in  width  they  become  much  crowded  together  and  thickened. 
.  .  .  The  crowding  together  of  the  median  segments  is  not  due  to  contraction, 
but  seems  to  be  a  permanent  characteristic  of  the  species. "  Concerning  the 
posterior  segments  Linton  noted  further  (1890:729)  that  in  the  dead  specimen 
taken  from  Histiophorus  gladius,  actually  No.  16.461  referred  to  above,  "The 
margins  of  the  strobila  are  apparently  entire.  The  segments  are  very  short, 
with  their  posterior  edges  slightly  wavy  on  the  median  segments,  thus 
suggesting  those  of  D.  plicatum.  The  posterior  edges  of  the  median  seg- 
ments are  crowded  together  like  the  edges  of  the  leaves  of  a  book  about  0.2mm. 
apart.  Near  the  posterior  end  they  are  not  so  closely  crowded,  being  about 
0.4mm.  apart."  (Fig.  73).  Confirmatory  frontal  sections  showed  that  this 
"entire"  nature  of  the  edge  of  the  strobila  is  in  reality  due  to  partial  decompo- 
sition; yet  at  the  same  time  the  surficial  portions  of  the  posterior  borders  of 


425] 


PSEUDOPHYLLIDEA  FROM  FISHES— COOPER 


137 


the  segments  did  not  seem  to  be  much  affected.  In  addition  it  should  be  noted 
that  besides  being  "not  so  closely  crowded"  the  segments  at  the  extreme 
posterior  end  of  this  strobila  are  relatively  much  narrower,  as  a  matter  of 
fact,  only  two-fifths  as  wide  as  the  widest  part  of  the  strobila.  This  seems 
to  be  quite  comparable  to  the  elongation  of  the  posterior  end  of  Schistocephalus 
when  it  reaches  the  final  host  and  matures. 

Another  important  characteristic,  which  should  be  mentioned  here  in  deal- 
ing with  the  external  features,  is  that  "In  alcoholic  specimens  a  dark  m.edian 
line  will  be  noticed  extending  from  the  posterior  end  to  the  middle  or  anterior 
third  of  the  strobila.  This  is  due  to  the  centrally  situated  ovaries  [uterus- 
sacs]  which  are  crowded  with  eggs;"  while  "a  median  furrow  on  one  of  the 
lateral  [surficial]  faces  of  the  body  begins  toward  the  anterior  and  becomes 
punctate  towards  the  posterior  region,  where  the  minute  lateral  genital  aper- 
tures become  visible  in  a  zig-zag  row. " 

The  following  table  gives  comparative  measurements  of  several  strobilas, 
the  first  columns  being  the  data  given  by  Linton: 


1 

2 

3 

4711,  U.S.N.M. 

Specimen 

Data  by 
Linton 

Data  by 

the 

writer 

16.461 

Length  of  strobila 

133mm. 
3.50 
1.00 

140mm. 
3.00 
0.90 
0.80 

20mm. 
2.10 
0.80 
0.60 

115mm. 

2;2.5;1.5 

1;1;1.2 

220mm. 

Length  of  scolex 
Breadth  of  terminal  disc 
Breadth  just  behind  terminal  disc 

2.0 
0.94 

Breadth  at  middle  of  scolex 

0.64 
0.44 
0.81 
0.89 
1.05 
0.58 
0.63 
0.39 
0.54 
0.89 

Breadth  at  constriction 

0.21 

0.31 

Breadth  posteriorly 

Depth  of  terminal  disc 

Depth  at  middle 

0.90 

Depth  at  constriction 

Depth  posteriorly 

Length  of  first  segment 

Breadth  of  same  anteriorly 
Breadth  of  same  posteriorly 

0.42 
0.80 

0.28 
0.50 
0.90 
0.12 

Maximum  breadth  of  strobila 

3.5 

5.0 

Length  of  widest  segments 
Breadth  of  posterior  end  of  stro- 
bila 

2.0 

Maximum  thickness  of  same 

1.5 

Concerning  the  cuticula  Uttle  can  be  said,  since  the  material  studied  was 
very  poorly  preserved.  Only  in  sections  of  a  very  young  strobila  was  it  seen 
with  any  degree  of  certainty.  There  it  was  found  to  be  about  4.5jLt  in  thick- 
ness, and  divided  by  differences  in  degree  of  staining  into  a  dark  cuter  one- 


138  ILUNOIS  BIOLOGICAL  MONOGRAPHS  [426 

third  composed  of  very  closely  set  "cini"  and  an  inner  two-thirds,  which 
took  the  stain  with  great  avidity,  leaving  only  a  thin  outer  lighter  part  which 
by  its  contrast  in  color  with  the  cirrous  stratum  served  to  set  the  latter  off  dis- 
tinctly from  the  much  thicker  inner  and  more  homogeneous  part.  The  cuticu- 
la  was  not  found  to  be  in  any  way  specially  modified  on  the  scolex,  altho  such 
might  be  found  to  be  the  case  in  well-preserved  material.  It  was  naturally 
retained  in  its  entirety  only  within  the  bothria. 

Only  in  the  smallest  strobilae  could  the  subcuticula  be  made  out  satisfactor- 
ily. It  is  from  25  to  40/i  in  thickness,  and  composed  of  somewhat  conical  cells, 
the  inner  ends  of  which  are  quite  cylindrical  while  the  outer  are  much  branched, 
divergent  and  interlacing.  Hence  the  cylindrical  portions,  proximal  to  the 
nuclei  and  usually  some\\^hat  smaller  in  diameter  than  the  latter,  are  seen  to 
stand  out  distinctly  and  quite  separately  from  the  much  less  dense  imderlying 
parenchyma.  The  outer  dendritic  portions  cannot  be  allotted  with  certainty 
to  their  proper  cell  bodies  on  account  of  this  complicated  mesh-work  which 
they  form  just  beneath  the  cuticula,  but  they  can  be  followed  to  the  cuticula, 
their  attachment  to  which  is  readily  seen. 

Chalk-bodies  in  the  poorly  preserved  parench)mia  are  usually  elliptical  in 
outline,  with  maximum  lengths  and  -w-idths  of  18  to  26  and  11  to  15ju,  respec- 
tively. They  are  fairly  nmnerous  and  scattered  thruout  all  parts  of  the 
strobila,  being  most  plentiful  in  the  cortex  of  ripe  proglottides.  In  the  scolex 
a  very  few  small  ones  are  to  be  foimd  only  in  the  enlarged  posterior  portion 
of  the  organ,  where  they  are  confined  to  the  medulla,  no  doubt  on  account  of 
the  great  development  of  the  musculature.  They  are  also  more  nimaerous 
perhaps  in  the  medullary  portion  of  the  parenchyma  of  the  anterior  segments 
than  in  the  cortical  region.  In  general  it  would  seem  that  they  are  developed 
in  that  portion  of  the  parenchyma  which  is  little  occupied  by  other  tissues 
or  organs,  chiefly  muscles  or  genitaUa, 

The  musculature  of  this  species  is  very  well  developed  and  powerful.  It 
was  described  by  Linton  (1890:729);  but  since  his  description  is  somewhat 
difficult  to  follow,  the  main  features  of  its  arrangement  will  here  be  given  even 
at  the  expense  of  reporting  much  that  has  already  been  reported. 

The  frontal  series  is  well  developed  and  consists  of  two  layers  on  each  sur- 
face of  the  strobila,  an  outer,  just  outside  of  the  thick  layer  of  main  longitudinal 
muscles,  and  an  inner,  just  within  this  or  bounding  the  very  thin  medullary 
parenchyma  outwardly,  as  shown  in  figure  87,  In  the  anterior  segments  a 
third  series  of  frontal  fibres  appears  as  the  posterior  flaring  border  of  the  seg- 
ment is  approached.  It  forms  a  ring  around  the  whole  strobila,  i.e.,  connecting 
with  its  fellow  of  the  opposite  surface  laterally,  unlike  the  other  two  layers, 
just  within  the  subcuticula  or  a  little  more  than  half  way  from  the  outer  edge 
of  the  layer  of  main  longitudinal  fibres  to  the  cuticula.  This  series  as  evidently 
pointed  out  by  Linton,  di\'ides  just  ahead  of  the  bay  behind  the  posterior 
border  of  the  segment,  part  of  it  going  to  the  outer,  posterior  border  and  the 
rest  remaining  ^\'ithin.  WTiile  the  latter  as  just  indicated  does  not  go  far 
posteriorly,  the  former  passes  to  the  hinder  edge  of  the  salient  border.    In 


427 J  PSEUDOP'HYLLIDEA  FROM  FISHES— COOPER  139 

mature  proglottides  the  layer  of  frontal  fibres  just  external  to  the  main  longi- 
tudinal group  is  greatly  thickened  close  to  the  posterior  border  of  the  segment. 
There  it  forms  a  transverse  ropelike  strand,  no  doubt  owing  in  part  at  least  to 
the  mmierous  vitelline  follicles  situated  in  the  cortex  between  these  levels. 
And  this  statement  applies  in  like  manner,  but  especially  more  towards  the 
median  Hne  of  the  strobila,  to  the  irmermost  series  of  frontal  muscles.  These, 
however,  are  further  interfered  with  chiefly  by  the  uteri  and  cirrus-sacs. 

The  sagittal  or  dorsoventral  fibres  are  quite  prominent  on  account  of  the 
fact  that  they  are  arranged  in  bundles  which  in  the  anterior  segments  find  their 
way  from  the  medulla  out  into  the  cortex  between  the  fasicles  of  the  main 
longitudinal  series.  They  are  less  numerous  laterally  than  medially.  In 
mature  segments,  on  the  other  hand,  they  are  crowded  and  somewhat  oblit- 
erated medially  by  the  large  genital  organs,  and  are  consequently  more  num- 
erous laterally,  that  is,  beyond  the  edges  of  the  uterus-sacs.  Longitudinal 
sections  show  that  large  numbers  of  them  pass  to  the  tip  of  the  salient  posterior 
borders  of  the  segments  and  hence  serve  to  retract  the  latter. 

The  longitudinal  muscles  are  present  in  two  groups,  an  inner,  or  main, 
and  an  outer  series.  The  former  appears  as  a  very  conspicuous  layer  of  large 
fibres  arranged  in  fasicles  or  bundles  on  each  surface  of  the  strobila  and  occupy- 
ing one-half  or  more  of  the  dorsoventral  diameter  of  the  cortical  parenchyma. 
The  latter  are  on  the  average  much  smaller,  less  numerous,  more  dispersed,  and 
situated  in  the  portion  of  the  cortex  between  the  outer  frontal  fibres  and  the 
cuticula.  In  the  anterior  segments  the  layer  of  irmer  fibres  is  about  70/x  in 
thickness  in  the  median  line,  and  thins  out  gradually  laterally  where  it  joins 
its  fellow  of  the  opposite  surface  by  a  few  fibres  which  lie  in  the  plane  of  the 
flat,  ribbon-like  medulla  (Fig.  87).  Linton  does  not  seem  to  have  noticed  this 
lateral  union  of  the  two  layers,  since  he  said  that  "  It  [the  longitudinal  muscle 
layer]  is,  moreover,  interrupted  at  the  margins  where  it  is  penetrated  by  the 
margins  of  the  inner  core  [the  medulla]."  Farther  back  where  the  segments 
become  very  broad  and  short  it  averages  about  85/i  in  thickness,  while  in  mature 
proglottides  the  thickness  amounts  to  145^t.  At  the  same  time  the  fasicles, 
in  the  anterior  segments  quite  rectangular  in  outline,  the  longer  diameter 
being  dorsoventral  in  direction,  become  more  elliptical  in  transection. 
In  the  latter  case  the  individual  fibres  are  circular  to  eUiptical  in  trans- 
verse section  and  have  a  maximum  diameter  of  15/1.  In  describing  this  group 
of  longitudinal  muscles  in  "transverse  sections  made  thru  that  part  of  the 
body  which  is  immediately  in  front  of  the  segments  that  contain  ripe  ova," 
Linton  stated  that  they  "...  are  very  large,  altho  not  at  this  point  in  distinct 
fasciculi. "  This  was  not  found  to  be  the  case  in  the  sections  studied  by  the 
writer,  since  fasciculi  were  seen  all  along  the  strobila  even  in  the  base  of  the 
scolex,  altho  it  is  true  that  anteriorly  they  are  separated  by  only  a  small  amount 
of  parenchyma  besides  the  bundles  of  sagittal  fibres  passing  between  them.  As 
regards  the  other  series  of  longitudijial  fibres  Linton  rightly  observed  that  "the 
longitudinal  fibres  of  the  inner  part  of  the  granular  layer  [here  described  as  the 
outer  portion  of  the  cortex]  do  not  differ  essentially  from  those  of  the  longi- 


140  ILUNOIS  BIOLOGICAL  MONOGRAPHS  [428 

tudinal  muscle  layer  proper,  except  that  they  are  more  scattered.  ..." 
Centrally  the  individual  fibres  of  this  group  are  of  the  same  diameter  as  the 
smallest  of  the  main  group,  while  peripherally  they  dwindle  ia  size  as  they 
approach  the  cuticiila  to  such  an  extent  that  there  they  are  indistinguishable 
from  the  longitudinal  cuticular  fibres.  Longitudinal  sections  show  that  they 
bear  the  same  relations  to  the  salient  posterior  borders  of  the  segments  as  are 
described  here  for  Clestohothriutn  crassiceps  and  other  species  and  emphasized 
by  Liihe  (1897a).  Anteriorly  a  number  of  them  pass  off  into  the  posterior 
border  in  the  typical  manner ;  but,  as  might  be  expected,  they  are  comparatively 
scarce  in  the  posterior  reaches  of  the  strobOa.  Again,  Linton  stated  that ''  the 
longitudinal  muscular  fibres  in  general  do  not  lie  parallel  with  each  other." 
This  was  found  to  be  more  strictly  applicable  to  those  within  the  fasicles,  since 
only  a  comparatively  few  fibres  pass  from  fasicle  to  fasicle  longitudinally. 
Bvt^,  as  in  other  species,  they  are  continuous  from  segment  to  segment  as  are 
indeed  all  of  the  groups  of  muscles,  so  that  as  far  as  their  general  arrangement 
is  concerned,  Linton's  (1890:731)  statements  are  thoroughly  justified: 

"Longitudinal  sections  were  carried  thru  several  contiguous  segments.  In 
these  there  were  no  septa  to  indicate  a  division  of  the  body  into  true  segments. 
The  only  indication  of  a  segmented  condition  is  the  superficial  character  of 
the  projecting  posterior  edges.  The  longitudinal  muscles  are  continuous  and 
the  ovaries  [uterus-sacs]  are  crowded  together  so  as  to  form  an  ahnost  un- 
broken zig-zag  line.  So  far  as  any  internal  characters  go,  the  body  is  prac- 
tically continuous." 

The  musculature  of  the  scolex  is  especially  well  developed,  the  sagittal 
and  radial  fibres  being  very  numerous.  An  unusual  augmentation  in  the 
number  of  the  former  appears  towards  the  outside  of  the  walls  of  the  bothria, 
extending  from  the  dorsal  to  the  ventral  surface.  Their  exact  course  is  ob- 
scured somewhat  laterally  in  the  median  frontal  plane  by  the  interdigitation 
of  the  radial  fibres  which  takes  place  there,  that  is,  opposite  the  lateral  grooves. 
As  the  posterior  borders  of  the  scolex  are  approached  they  diminish  in  number 
and  size  and  eventually  disappear.  Coming  into  the  base  of  the  scolex  as  an 
eUiptical  ring  in  cross-section  with  its  thickness  almost  as  much  laterally  as 
dorsoventrally,  the  layer  of  main  longitudinal  muscles  soon  sends  out  dorso- 
ventral  horns  into  the  walls  of  the  bothria  on  each  side  and  becomes  arranged 
in  general  much  as  in  Clestobothrium  crassiceps — doubtless  an  adaptation  to 
the  almost  closed  natiu-e  of  the  bothria.  The  outer  longitudinal  fibres  are 
arranged  on  each  side  of  the  scolex  as  a  continuous  lateral  band  between  the 
lateral  sagittal  fibres  just  mentioned  and  the  cuticula,  and  extending  from  the 
dorsal  to  the  ventral  surface.  Each  bothriimi  has  a  much  smaller  and  thinner 
band  on  each  side  next  to  the  cuticula  lining  its  cavity.  The  terminal  disc  is 
almost  completely  filled  up  with  very  powerful  longitudinal  arcuate  fibres  for 
the  protrusion  of  its  edges. 

In  the  anterior  segments  the  two  chief  nerve  strands  are  situated  in  the 
medullary  parenchyma  between  the  lateral  and  median  quarters  of  the  trans- 
verse diameter  of  the  strobila.    From  18  to  30/i  in  diameter,  they  fill  up  the 


4291  PSEV DOPEY LLIDEA  FROM  FISHES— COOPER  141 

whole  of  the  medulla  dorsoventrally  at  these  points.  In  mature  proglottides 
they  have  the  same  relative  positions  in  the  frontal  plane,  but  are  located  in 
the  ventral  one-half  of  the  medulla,  their  transverse  diameter  being  as  much 
as  50)u.  In  the  scolex  each  expands  opposite  the  edges  of  the  terminal  disc  to 
form  a  ganglion,  which  sends  out  a  large  branch  to  each  of  the  two  quadrants 
of  the  disc  on  the  same  side,  and  connects  with  its  fellow  by  a  slightly  narrower 
commissure. 

Four  main  longitudinal  excretory  vessels  maintain  a  constant  course 
thruout  the  anterior  segments.  These  are  arranged  in  two  pairs,  a  more  median 
and  a  lateral,  not  in  the  same  plane  in  the  medulla.  The  members  of  the 
latter  are  the  larger  and  are  situated  at  the  sides  of  the  median  one-quarter 
of  the  transverse  diameter  of  the  segment.  All  of  these  vessels  are  connected 
at  various  levels  by  large  branches  to  form  an  extensive  plexus  thruout  the 
medulla.  In  the  posterior  crowded  segments,  however,  the  main  vessels 
become  lost  in  the  plexus,  altho  here  and  there  they  seem  to  occupy  their  origi- 
nal positions  thru  a  few  sections.  Only  two  large  vessels,  probably  the  lateral 
pair,  giving  off  many  branches  of  the  same  calibre,  can  be  followed  with  cer- 
tainty into  the  scolex.  About  half  way  to  the  summit  of  the  terminal  disc 
they  break  up  into  a  plexus  which  ramifies  thruout  the  walls  of  the  bothria. 
The  posterior  end  of  the  smallest  strobila  at  hand  showed  the  same  sort  of 
communication  of  a  terminal  plexus  with  the  exterior  thru  large  side  branches 
and  foramina  secundaria  as  in  B.  scar  pit. 

Linton  (1889:457)  described  the  reproductive  organs  in  general  in  the 
following  words:  "In  alcohoUc  specimens  a  dark  median  line  will  be  noticed 
extending  from  the  posterior  end  to  the  middle  or  anterior  third  of  the  strobila. 
This  is  due  to  the  central*  situated  ovaries  [uterus-sacs],  which  are  crowded 
with  eggs.  The  genital  apertures  are  lateral  and  may  be  traced  in  an  irregular 
zig-zag  line  on  one  side  from  about  the  anterior  third  of  the  body.  In  the 
mature  segments  they  are  rendered  obscure,  if  not  wholly  obUterated,  by  the 
mass  of  eggs  with  which  the  center  of  the  segment  is  filled,"  and  later  (1890: 
729,  730)  besides  giving  the  external  features,  quoted  above,  stated  that  "The 
reproductive  apertures  are  near  the  median  line  on  one  of  the  lateral  sides. 
They  are  very  close  together  and  rather  small.  Each  aperture  represents  a 
pair  of  sexual  organs,  cirrus  and  vagina.  Upon  making  a  few  longitudinal 
sections  on  the  lateral  [dorsal]  face  which  bears  the  reproductive  apertures, 
the  small  vaginal  opening  comes  into  view.  It  opens  into  the  common  aperture 
from  behind  and  near  the  surface.  The  large  aperture  continues  into  the  cirrus- 
bulb.  ..."  Linton  correctly  stated  that  the  common  genital  openings  are 
arranged  *  in  a  zig-zag  row"  in  the  median  Une,  as  shown  in  figure  73;  but  much 
of  this  irregular  lateral  displacement  in  the  mature  proglottides  would  seem 
to  be  due  to  lateral  pressure  exerted  by  other  organs,  probably  the  gorged 
uterus-sacs  or  at  least  the  uterine  ducts,  since  in  immature  segments  where 
the  cirrus-sacs  are  already  well  developed,  they  are  almost  exactly  in  the 
median  line.  In  sagittal  sections  the  genital  cloaca  is  seen  to  open  to  the 
exterior  at  about  the  middle  of  the  length  of  the  very  short  mature  proglottis 


142  ILLINOIS  BIOLOGICAL  MO.YOGR.iPHS  [430 

and  to  be  in  many  cases  just  covered  by  the  posterior  border  of  the  segment 
immediately  ahead.  It  is  in  the  form  of  a  narrow  tube,  often  somewhat 
enlarged  ventrally,  %v'ith  a  length  of  from  85  to  llS/z  and  extending  at 
right  angles  to  the  general  surface  of  the  strobila.  A  secondary  genital 
cloaca  or  ductus  hermaphroditicus  is  present  at  the  bottom  of  this  tube  and  is 
separated  from  the  latter  by  a  valve-like  muscular  extension  of  its  walls 
(Fig.  88).  Behind.this  the  cirrus  is  often  found  partially  extended  and  directed 
backward  towards  the  opening  of  the  vagina  or  actually  in  contact  with  the 
vaginal  sphincter.  No  sphincter  muscle  surrounding  the  genital  cloaca  at 
any  level  was  found,  altho  a  number  of  frontal  fibres  of  the  body  muscles, 
curving  around  the  structure  both  ahead  and  behind  have  the  general  appear- 
ance of  such  a  structure.  Very  early  traces  of  the  reproductive  rudiments 
were  found  in  sections  of  segments  75mm.  from  the  tip  of  the  scolex  of  one  of 
the  largest  strobilas  studied. 

The  testes,  continuous  from  proglottis  to  proglottis,  are  spherical  to  ellip- 
soidal in  shape,  with  their  longest  axes  usually  transverse  in  the  latter  case. 
The  measurements  from  sections  are  as  follows:  width,  64  to  75/i;  length,  45 
to  60;  depth,  64  to  80.  On  account  of  their  being  closely  and  irregularly  crowd- 
ed in  the  very  short  segments  no  attempt  was  made  to  count  them  directly; 
but  the  average  number  in  the  transverse  sections  (22  to  23)  multiplied  by 
the  average  for  each  proglottis  from  sagittal  sections  of  a  long  series  of  seg- 
ments (3  to  4)  gave  about  67.  The  correct  number  is  probably  between  60 
and  70.  They  are  arranged  in  a  layer  in  the  dorsal  half  of  the  medulla,  where 
they  show  some  tendency  towards  stratification.  A  few,  however,  were  found 
outside  of  the  medulla,  that  is  beyond  the  inner  frontal  muscles  and  between 
fasciculi  of  the  main  longitudinal  musculature. 

The  vas  deferens  forms  a  compact  mass  of  coils,  closely  applied  dorsolateral- 
ly  to  the  proximal  deflected  end  of  the  cirrus-pouch,  and  alternating  irregularly 
from  side  to  side  constantly  opposing  the  uterus-sac.  In  ripe  proglottides  it 
is  quite  compressed  anteroposteriorly  by  the  uterine  tube,  and  also,  as 
a  consequence,  often  extends  thruout  almost  the  whole  of  the  medulla 
dorsoventrally,  in  which  case  it  is  crescentic  in  outline  in  transverse  sections 
with  the  concave  side  directed  towards  the  median  line  so  as  to  somewhat  sur- 
roimd  the  cirrus-sac.  The  average  measurements  of  the  mass  of  coils  are: 
length,  0.085mm;  width,  0.175;  depth,  0.400.  While  it  was  found  impossible 
to  measure  satisfactorily  the  size  of  the  duct,  gorged  with  sperms  in  the  mass, 
it  was  seen  to  enter  the  base  of  the  very  muscular  cirrus-sac  with  a  diameter 
of  7.5/*.  Within  the  latter  it  expands  to  15/i  and  proceeds  with  this  caliber 
in  the  form  of  a  compact  lot  of  close  and  somewhat  spiral  coils  for  about  one 
quarter  of  the  length  of  the  pouch.  In  the  second  quarter,  i.e.,  from  the 
ventral  end  of  the  sac,  it  pursues  a  straight  course  and  evidently  functions  as 
a  quite  eflicient  sperm  receptacle  since  it  is  here  usually  from  twice  to  three 
times  as  large  as  before.  In  the  dorsal  half  of  the  pouch  it  again  dimishes  to 
from  5  to  7/x  and  continues  still  in  a  straight  course  to  the  opening  as  the  cirrus 
proper.    Thruout  its  whole  course  its  wall  is  very  thin,  including  only  a  very 


431]  PSEUDOPHYLLIDEA  FROM  PISHES— COOPER  143 

few  circular  and  longitudinal  muscle  fibres.  Distally  the  cuticular  lining  is 
reduced  to  a  minimum.  Thus  the  cirrus  when  protruded,  usually  for  a  short 
distance  only,  is  a  comparatively  weak  structure  with  thin  walls,  but  a  diameter 
at  the  base  of  from  30  to  35m-  It  is  also  quite  short  since  in  no  place  in  the 
sections  made  was  it  found  extended  more  than  half  way  to  the  external  opening 
of  the  genital  cloaca,  but  more  often,  as  noted  above,  turned  around  in  the  duc- 
tus hermaphroditicus  towards  the  vaginal  opening.  Thus  it  is  evidently 
adapted  to  the  function  of  simply  conveying  the  spermatozoa  to  the  latter 
orifice  in  the  act  of  self-impregnation  rather  than  of  acting  as  an  intromittent 
organ  in  cross-fertilization.  The  diameter  of  the  retracted  cirrus  was  given 
by  Linton  (1890:730)  as  0.008mm. 

The  cirrus -sac  is  comparatively  long  and  cylindrical  and  extends  from  the 
inner  boundary  of  the  genital  cloaca  to  the  median  frontal  plane  of  the  pro- 
glottis. While  its  dorsal  half  is  situated  more  at  right  angles  to  the  surface, 
its  ventral  half  bends  over  in  the  transverse  plane  to  the  right  or  left  to  become 
related  to  the  coiled  vas  deferens  in  the  manner  described  above.  This  deflec- 
tion of  its  proximal  end  thus  alternates  irregularly  with  the  latter,  and  is  always 
away  from  the  uterus-sac.  The  maximum  length  and  diameter  in  the  latter 
case  in  the  dorsal  half  of  the  organ  are  0.500  and  0.145mm.,  respectively.  As 
shown  in  figure  88,  and  as  noted  by  Linton,  the  walls  are  very  thick,  leaving 
only  a  comparatively  narrow  cavity  to  accommodate  the  cirrus;  they  are  com- 
posed of  a  very  powerful  inner  layer  of  circular  muscles  surrounded  by  a  thin 
layer  of  longitudinal  fibres  which  do  not  have  any  points  of  attachment  to  the 
body-wall,  so  far  as  could  be  determined.  The  space  surrounding  the  ejacula- 
tory  duct  and  cirrus  proper  accommodates  the  fine  and  quite  long  retractor 
fibres  and  a  small  amount  of  parenchymatous  tissue.  The  retractors  are  not, 
however,  as  large  or  numerous  as  in  the  previous  species  of  the  genus  in  which 
the  cirrus  is  better  developed. 

The  vagina,  which  opens  close  behind  the  cirrus  and  usually  somewhat 
towards  the  same  side  to  which  the  latter  is  deflected,  begins  with  a  bulb-like 
sphincter,  quite  like  that  described  and  figured  by  Linton  (1898:436)  for  his 
Dibothrium  laciniatum,  60ix  in  length  by  about  90  in  maximum  diameter.  The 
walls  of  this  structure,  40^t  in  thickness,  are  composed  of  two  layers  of  muscle 
fibres  of  equal  thickness:  an  outer  of  loose  circular,  and  an  iimer  of  somewhat 
radially  arranged  fibres.  The  whole  organ  would  thus  appear  to  be  adapted 
to  the  pumping  of  the  sperms  into  the  vagina.  The  latter  proceeds  ventrally 
with  a  diameter  of  about  25ju,  after  enlarging  considerably  immediately  behind 
the  bulb.  It  is  surrounded  by  circular  fibres  only.  At  the  level  of  the  ventral 
end  of  the  cirrus-sac  it  joins  the  oviduct. 

The  ovary,  which  has  an  average  width  of  0.45mm.,  is  irregularly  branched 
in  mature  proglottides,  much  compressed  anteroposteriorly  by  the  numerous 
coils  of  the  uterine  tube,  and  often  displaced  from  the  median  line  by  the  latter 
and  the  spacious  uterus-sac.  Furthermore,  while  the  isthmus,  itself  irregular  in 
shape  and  hence  somewhat  difficult  to  distinguish  from  the  rest  of  the  organ, 
*'lies  next  the  inner  side  of  the  lateral  [ventral]  muscular  wall,"  the  wings 


144  ILLINOIS  BIOLOGICAL  MONOGRAPHS  [432 

curve  upward  on  each  side,  sometimes  reaching  aknost  to  the  dorsal  boundary 
of  the  medulla.  The  oocapt  is  almost  spherical  in  shape  with  an  average 
diameter  of  30/i,  and  is  situated  in  the  median  line.  The  oviduct  immediately 
beyond  the  narrow  outlet  of  the  oocapt  is  25/i  in  diameter.  At  the  point  of 
union  of  the  vagina  with  the  oviduct  there  seems  to  be  a  vestibule,  similar  to 
that  of  B.  SCOT  pit,  but  this  was  not  made  out  to  the  writer's  satisfaction.  Two 
vitelline  ducts,  each  about  ISju  in  diameter,  unite  at  about  the  level  of  the  oocapt 
and  continue  dorsaUy  mth  the  same  diameter  as  the  common  vitelline  duct. 
This  turns  downward  again  and  quickly  enlarges  to  form  the  vitelline  reservoir, 
which  was  f oimd  to  have  a  maximum  diameter,  when  filled  with  yolk  cells  of 
about  60^1.  The  vitelline  follicles  are  extremely  nvmierous  and  very  closely 
arranged  in  the  cortical  parenchyma  in  two  lateral  fields,  a  median  strip  being 
left  free  of  them  on  each  surface  of  the  strobHa.  They  are  eUipsoidal  in  shape, 
with  average  maximimi  lengths,  widths  and  depths  of  35,  60  and  85/*,  respec- 
tively. In  the  material  studied  they  showed  considerable  tendency  towards 
stratification  and  on  account  of  this  fact,  their  very  varying  size  and  the  poor 
condition  of  their  walls,  no  satisfaction  was  experienced  in  attempting  to  deter- 
mine the  approximate  number  for  each  segment;  but  it  must  be  weU  over  one 
thousand  from  a  comparison  of  the  sections  v/ith  those  of  B.  cuspidatus. 

The  uterine  duct  begins  approximately  in  the  median  line,  quickly  expands 
between  the  cirrus  pouch  and  the  ovary,  first  in  the  direction  of  the  coiled  vas 
deferens  and  as  far  laterally  as  the  edge  of  the  ovary,  and  then  crosses  the  me- 
dian line  to  the  opposite  side  where  the  mass  of  coils,  occupying  the  whole  dorso- 
ventral  diameter  of  the  medulla,  further  enlarges  gradually  in  aU  directions 
and  joins  the  comparatively  large  uterus  sac.  In  toto  preparations  the  duct 
and  sac  are  seen  to  form  a  continuous  club-shaped  mass  gorged  with  eggs  and 
with  the  larger  end,  the  sac,  alternating  irregularly  from  side  to  side.  This 
irregular  alternation  of  the  uterus-sacs  was  evidently  not  noticed  by  Linton 
since  he  spoke  of  only  "a  dark  brown  median  stripe  made  by  the  ripe  ova  in 
the  crowded  ovaries  [uteri]  ";  but  Ariola  (1900:410)  said  of  them:  "Le 
masse  ovariche  spesso  sono  irregolarmente  collocate  da  ima  parte  e  dall'  altra 
della  linea  mediana."  Only  in  sections  can  one  distinguish  the  sac  from  the 
duct,  since  the  two  are  so  closely  applied  to  each  other.  In  dorsoventral  view 
the  uterus-sac,  itself,  is  somewhat  circular  in  outline,  when  not  pressed  against 
one  of  its  fellows  ahead  or  behind,  and  has  a  maximum  diamet*  of  0.45mm. 
Ventrally,  however,  it  is  funnel-shaped.  As  shown  in  figure  73,  it  may  become 
so  enlarged  as  to  invade  the  adjoining  proglottides  to  a  considerable  extent. 
The  aperture  is  located  in  the  middle  of  the  sac  and  consequently  forms  with 
its  fellows  two  lines  of  irregularly  alternating  pores  on  the  ventral  surface  of  the 
strobila,  about  1.0mm.  apart.  It  is  only  about  20ju  in  diameter,  and  is  situated 
towards  the  anterior  border  of  the  proglottis,  often  well  under  the  overlapping 
posterior  border  of  the  segment  ahead.  The  lowermost  or  funnel-shaped 
portion  of  the  sac,  little  more  than  that  which  passes  through  the  stratum  of 
longitudinal  muscles,  is  surrounded  by  a  thick  layer  of  material,  as  shown  in 
figure  97,  the  nature  of  which  was  not  determined  satisfactorily.    It  appears 


433]  PSEUDOPHYLLIDEA  FROM  FISHES— COOPER  145 

to  be  glandular  in  nature,  altho  muscle  fibres  traverse  the  mass  in  several  direc- 
tions, the  inner  of  them  being  longitudinal  and  the  outer  circularly  oblique. 
Altho  this  structure  may  have  a  glandular  function  in  connection  with  the 
passage  of  the  eggs  to  the  exterior,  it  obviously  acts  as  a  powerful  sphincter 
controlling  the  same  and  permitting  perhaps  of  the  laying  of  only  a  few  at  a 
time.  Distal  to  the  outer  end  of  the  funnel,  where  it  loses  these  fibres,  the 
sac  continues  through  the  cortical  parench3ana  as  a  narrow  tube  to  the  pore. 

The  eggs  of  this  species  were  said  by  Linton  (1889  and  1890)  to  be  of  two 
kinds:  "...  one  yellowish  in  moimted  specimens  with  a  strong  shell,  in  some 
cases  white  and  opaque;  another  sort  transparent,  with  a  very  thin  shell." 
These  differences  were  seen  in  the  material  studied,  but  they  were  considered 
to  be  merely  due  to  differences  of  age,  the  thinner-shelled  ones  being  the 
younger.  While  the  same  author  gave  the  length  and  breadth  as  45  to  54/* 
and  27  to  30n,  respectively,  the  writer  found  their  maximum  dimensions  to  be 
in  sections  58  by  34/f. 

The  materia]  studied  consisted  of  two  lots:  No.  4711,  in  the  collection  of 
the  United  States  National  Museimi,  from  the  rectum  of  Tetrapterus  sp.  from 
Penekese,  determined  by  Linton;  and  No.  16.461  in  the  collection  of  the 
University  of  Illinois,  from  the  intestine  of  Histiophorus  gladius,  obtained  from 
Prof.  Linton,  and  evidently  the  actual  specimen  described  by  him  in  1890. 
The  details  of  the  anatomy,  here  given,  were  studied  from  confirmatory  sec- 
tions of  the  latter. 

DIBOTHRIUM  LACINIATUM  Linton 

Linton  (1898:425)  established  this  species  on  the  basis  of  the  material 
contained  in  lot  No.  4741  of  the  collection  of  the  United  States  Museum  from 
Tarpon  atlanticus,  and  again  reported  it  from  the  same  host  species  in  1901 
(p.  437).  Liihe  (1899:43)  in  his  list  of  the  species  of  the  genus  Bothriocephalus 
s.  str.  remarked  that  "Von  weniger  gut  bekannten  Arten  gehoren  anscheinend 
noch  hierher  Bothriocephalus  laciniatus  (Lint.)  und  occidentalis  (Lint.);"  while 
Ariola  (1900:414)  also  placed  it  in  the  same  genus,  as  he  conceived  the  latter 
to  be  constituted. 

During  the  study  of  B.  manuhriformis  the  writer  was  impressed  with  the 
great  resemblance  between  D.  laciniatum  and  it,  in  all  but  a  few  details,  the 
two  being,  in  fact,  identical.  The  measurements  for  length  and  maximum 
breadth,  as  shown  in  the  comparative  table  below,  agree,  while  those  of  the 
scolex  and  anterior  segments  are  as  near  as  can  be  expected  from  cestode 
material  which  is  found  in  various  degrees  of  contraction  and  relaxation.  All 
of  the  conditions  represented  in  Linton's  (1898)  Figs.  7  to  12,  PI.  XXX,  were 
observed  in  the  material  of  B.  manuhriformis  studied — when  such  obvious 
errors  as,  "  Fossettes  marginal  as  to  head,  corresponding  to  the  flat  surface  of 
the  body, "  are  taken  into  consideration — ^while  the  description  of  the  external 
features,  excepting  that  of  the  posterior  segments,  applied  in  detail.  But 
later  lot  No.  4741,  U.S.N.M.,  was  obtained  by  Professor  Ward,  and  the  writer 


146  ILUNOIS  BIOLOGICAL  MONOGRAPHS  [434 

learned  that  his  suspicions  were  well  founded;  for  D.  laciniatum  proved  to  be 
identical  with  B.  manubriformis.  The  posterior  segments  "with  breadth  one 
and  a  half  times  the  length"  had  different  proportions  from  those  obser\'ed  in 
mature  material  of  the  latter  species,  because  they  were,  altho  gravid,  of  quite 
yoimgers  trobilas.  The  material  of  No.  4741  is,  in  fact,  intermediate  between 
No.  4711  of  B.  numubriformis  and  the  16.461  of  the  same  species  dealt  with 
above,  not  so  much  in  size  since  it  does  not  show  the  regions  so  well,  as  in  degree 
of  maturity.  The  fact  that  "  the  segments  are  not  uniform;  one  segment  with 
a  saUent  posterior  border  followed  by  about  two  with  less  saUent  borders"  is 
due  to  the  irregular  manner  in  which  the  primary  segment  divides  into  sub- 
segments.  The  dimensions  of  the  eggs  correspond,  while  the  measurements 
of  the  cirrus-bulb,  vaginal  sphincter  and  calcareous  bodies  are  the  same  in  the 
two  species.  Linton  stated  that  in  D.  laciniatum  "The  reproductive  cloacae 
lie  along  the  median  line  of  one  of  the  flat  surfaces  of  the  body.  The  external 
openings  of  the  uterus  lie  along  the  median  line  of  the  opposite  surface. "  WTiile 
the  former  was  found  to  be  the  case,  the  latter  was  not,  for  the  openings  of  the 
uteri  he  irregularly  on  either  side  of  the  median  line  as  in  B.  manubriformis. 
Furthermore,  the  cirrus-bulb  was  not  foimd  to  have  "its  inner  end  deflected 
to  the  right  [left,  when  we  take  into  consideration  the  fact  that  the  common 
genital  cloaca  of  D.  laciniatum  was  considered  to  open  on  the  ventral  instead 
of  the  dorsal  surface]  where  it  communicates  with  the  vas  deferens,  which 
lies  in  numerous  folds  in  front  and  to  the  right  of  the  cirrus-bulb,"  but  to 
alternate  irregularly  from  side  to  side  according  as  the  uterus-sac  and  distal 
end  of  the  uterine  duct  occupy  the  other  side  of  the  proglottis;  while  the  vas 
deferens  was  as  described  above  (p.  142).  Altho  the  vaginal  bulb  was  found 
to  be  a  little  larger  in  the  material  of  D.  laciniatum,  its  structure  and  position 
were  also  quite  as  in  5.  manubriformis.  On  the  other  hand  no  muscle  fibres 
completely  encircling  both  genital  apertures,  such  as  shown  in  Linton's  Fig. 
5,  PI.  XXXI,  were  seen,  but  what  might  easily  be  taken  for  such  were  formed 
by  the  crossing  of  much  curved  and  spread  longitudinal  and  transverse  fibres 
of  the  body  wall,  in  such  a  manner  that  the  portions  intersecting  at  the  four 
comers  run  in  almost  circular  directions  and  concentrically  parallel  to  each 
other  so  as  to  give  the  appearance  of  the  whole  forming  a  complete  ring  in  each 
case.  The  genital  cloaca  was  foimd  to  be  shallower  than  in  the  material  from 
Eistiophorus  gladius.  This  is  evidently  due  to  the  fact  that  the  proglottides 
were  yoimger  and  not  yet  gravid  as  in  those  from  the  latter  host.  The  uterus- 
opening  was  not  foimd  to  be  "lined  with  cilia"  but  with  irregular  ragged 
processes  which  are  e\idently  only  portions  of  the  lining  of  the  developing  fim- 
nel  and  the  external  duct  of  the  same.  Finally  the  position  and  structure  of 
the  ovary,  of  the  vitelline  reservoir  and  of  the  various  layers  of  the  body 
exactly  correspond  in  the  two  forms. 

Consequently  the  writer  feels  that  there  can  be  no  doubt  whatever  concern- 
ing the  identity  of  D.  laciniatum  with  B.  manubriformis,  which  fact  also  seems 
to  be  recognized  in  the  Fauna  of  the  Woods  Hole  Region  (Simmer,  Osbom 
and  Cole,  1913:  585)  where  the  former  is  not  found  among  the  cestodes,  altho 


435]  PSEUDOPHYLLIDEA  FROM  FISHES— COOPER  147 

the  host,  Tarpon  atlanticus,  is  listed.     Since  B.  manuhriformis  was  described 
before  D.  laciniatum,  the  latter  must  now  be  considered  as  a  species  delenda. 

BOTHRIOCPHALUS  HISTIOPHORUS  Shipley 

The  writer  would  also  hke  to  call  attention  in  this  place  to  the  fact  that 
Shipley's  (1901)  Bothriocephalus  histiophorus  agrees  in  all  essentials  with  B. 
manuhriformis,  which  is  almost  to  be  expected  since  both  are  found  in  the  same 
host  genus. 

The  description  and  figure  of  the  scolex  is  that  of  the  latter  species,  altho 
the  true  nature  of  the  bothria  was  not  ascertained  by  Shipley  on  account  of 
their  almost  closed  condition,  which  was  also  seen  in  many  specimens  of  B. 
manuhriformis  by  the  writer.  Consequently  it  was  described,  erroneously, 
as  "...  provided  with  longitudinal  slit-like  depressions  which  hardly  attain 
the  dignity  of  suckers  situated  in  the  dorsal  and  ventral  plane. "  The  external 
features  of  the  strobila  are  the  same  in  both  species,  altho  Shipley  was  describ- 
ing a  comparatively  young  specimen,  as  shown  in  his  measurements  of  the 
scolex  and  in  his  figures  showing  the  size  of  the  uterus-sac.  The  description 
and  figures  of  the  genitalia  agree  in  almost  all  details.  It  is  quite  apparent, 
however,  that  his  Fig.  V,  diagrammatic  it  is  true,  is  entirely  misleading  as  to 
the  proximal  connections  of  the  reproductive  ducts,  one  of  which,  the  ootype, 
he  confused  with  the  isthmus  of  the  ovary.  The  ova  in  the  latter  were  found 
by  the  writer  to  be  IS/x  in  diameter  in  B.  manuhriformis  as  in  B.  histiophorus. 
His  description  of  these  central  connections  of  the  genital  ducts  is  certainly 
not  that  of  the  genus  Bothriocephalus;  for  in  dealing  with  the  isthmus  of  the 
ovary,  which  he  called  the  ootype,  he  said  that  ''Into  this  region  opens  the 
small  shell-gland,  and  the  ducts  of  the  yolk  glands.  The  shell-gland  lies 
posteriorly  to  the  ovary  between  the  right  and  left  halves  of  that  organ  and 
with  the  ducts  of  the  yolk  glands  it  opens  into  the  ootype  posteriorly. "  The 
measurements  of  the  eggs  and  the  description  of  the  uterus  agree  with  those 
of  Linton's  species,  excepting  that  the  opening  of  the  uterus-sac  "...  does 
not  seem  to  be  provided  with  anything  of  the  nature  of  a  sphincter  muscle.  .  . " 
Altho  the  material  at  hand  did  not  permit  of  the  sectioning  of  such  young 
stages  in  the  development  of  the  uterus-sac,  it  would  seem  from  the  somewhat 
varying  nature  of  its  funnel-shaped  ventral  end,  described  above  for  B.  manu- 
hriformis, that  in  more  anterior  proglottides  it  might  be  in  such  a  condition 
as  to  be  easily  overlooked.  The  nature  and  arrangement  of  the  vitelUne  glands, 
the  vagina  and  its  bulb  or  sphincter,  the  testes  in  number  and  position,  and 
finally  the  cirrus-sac,  all  considered  in  connection  with  his  Figs.  I-IV,  force 
the  writer  to  the  conclusion  that,  so  far  as  can  be  determined  in  the  absence 
of  material  for  study,  Shipley's  B.  histiophorus  n.  sp.  is  identical  with  B.  manu- 
hriformis (Linton). 

Concerning  the  probable  disposal  of  ripe  eggs  in  B.  histiophorus,  Shipley 
made  a  statement  with  which  the  writer  can  agree,  since  it  seems  to  be  the 
natural  conclusion  to  arrive  at  after  a  study  of  the  varying  contents  of  the 
uterus-sac  along  the  strobila,  namely,  "From  what  I  have  seen  I  think  it  prob- 


148 


ILLINOIS  BIOLOGICAL  MONOGRAPHS 


436] 


able  that  eggs  pass  out  from  the  tapeworm  into  the  alimentary  canal  of  the 
host  and  that  in  B.  histiophorus  the  eggs  pass  freely  out  from  each  proglottis 
and  do  not  wait  until  the  posterior  proglottides  break  off  to  make  their  escape 
from  the  parent." 

In  the  following  table  a  number  of  important  measurements  of  B.  manu- 
hriformis,  D.  laciniatum  and  B.  histiophorus  are  given  for  the  sake  of  com- 
parison; all  dimensions  are  given  in  millimeters: 


D.  laciniatum 

B.  histiophorus 

B.  manubriformis 

Maximum  length  of  strobila 

154 
4 
2 
2 

0.8 
0.4 
0.6 
0.25 
0.5 
0.55 
0.35 
0.25 
0.7 
0.3 
0.65 
0.3 
0.3 
1 

1.5 
0.4 
0.14 
0.05 
0.07 
52x35m 
17-24x8-14m 

220 

Maximum  breadth  of  strobila 

5 

Breadth  at  posterior  end 
Length  of  scolex 
Breadth  of  terminal  disc 
Breadth  of  scolex  at  middle 

2 

1.8 
0.4 

1.5-3.5 

0.8-1.2 

0.64 

Breadth  at  posterior  end 

0.81 

Breadth  at  constriction 

0.21-0.44 

Depth  of  terminal  disc 

0.89 

Depth  of  scolex,  middle 

0.90-1.05 

Depth  at  posterior  end 

0.63 

Depth  at  constriction 

0.58 

Length  of  first  segment 

0.39 

Breadth  of  same  anteriorly 

0.28-0.54 

Breadth  of  sam^e  posteriorly 

0.50-0.89 

Length  of  median  segments 

0.3 

Breadth  of  median  segments 

Length  of  posterior  segments 
Breadth  of  same 
Length  of  cirrus-sac 

0.16  ("ripe") 
0.5    ("ripe") 

1.0 

2.50 

0.50 

Max.  diameter  of  same 

0.14 

Length  of  vaginal  sphincter 

0.05 

Diameter  of  same 

0.07 

Dimensions  of  eggs 
Dimensions  of  calcareous  bodies 

45x35ju 

58x34|u 
18-26x11-15^ 

Nimiber  of  testes 

50-70 
0.15 

60-70 

Diameter  of  ova  in  ovarian  isthmus 

0.15 

437]  PSEUDOPHYLLIDEA  PROM  FISHES— COOPER  149 

BOTHRIOCEPHALUS  OCCIDENTALIS  (Linton  1898) 
[Figs.  28,  89] 


1898 

Dibothrium  occideniale 

Linton 

1898 

:437 

1899 

Bothriocephalus  occidentalis 

Liihe 

1899 

:43 

1900 

Bothriocephalus  occidentalis 

Ariola 

1900 

:415 

Specific  diagnosis:  With  the  characters  of  the  genus.  Large  cestodes  with 
maximum  length  at  least  310mm.  and  breadth  5.5.  Scolex  small,  elongate 
and  somewhat  rectangular,  constricted  posteriorly,  1.3mm.  long  by  0.46  wide. 
First  segments  somewhat  funnel-shaped;  middle,  densely  crowded,  ten  to 
twenty  times  broader  than  long;  posterior  narrower  and  longer,  2  by  0.8nmi., 
in  groups  of  three  or  four. 

Cuticula  1.5/x  in  thickness.  Calcareous  bodies  18  by  13ju.  Longitudinal 
muscles  in  bimdles,  outer  series  very  scarce.  Four  chief  excretory  vessels, 
two  much  more  prominent  than  the  others. 

Genital  cloacae  form  a  narrow  zig-zag  row,  each  very  shallow,  no  velum, 
cloaca  and  hermaphroditic  duct  united.  Vagina  opens  directly  behind  the 
cirrus  or  a  little  to  one  side. 

Testes  divided  into  two  fields  on  each  side  by  the  nerve  strand,  75  to  90  in 
number,  25,  85,  and  115/i  in  average  maximimi  length,  breadth  and  depth. 
Coils  of  vas  deferens  loosely  arranged,  the  duct  25/i  in  diameter,  alternating 
irregularly  from  side  to  side  opposite  the  uterus-sac.  Cirrus  long  and  cylindri- 
cal, 0.23  by  0.06mm.,  walls  comparatively  thin,  most  of  the  circular  muscles 
being  towards  the  inner  end. 

No  vaginal  sphincter  nor  bulb.  Ovary  soHd,  unbranched,  0.5  to  0.6mm. 
wide,  0.04  long  and  0.13  to  0.18  deep.  Oocapt  25/i  in  diameter.  Vitelline  fol- 
licles very  numerous,  the  two  lateral  fields  on  each  surface  narrow,  leaving  a 
broad  median  strip  free,  25,  60  and  115/i  in  length,  breadth  and  depth,  respec- 
tively. ViteUine  reservoir  45/x  in  diameter.  Uterine  duct  voluminous  on  both 
sides  of  the  median  line,  crowding  all  other  organs.  Maximum  width  and  length 
of  uterus-sac,  0.65  and  0.25mm.,  respectively;  not  encroaching  much  on  neigh- 
boring proglottides;  ventral  portion  not  especially  modified.  Uterus-openings 
alternate  irregularly  from  side  to  side  near  the  median  line,  far  forward  in 
the  proglottides. 

Eggs  72  to  76  by  38  to  41/*,  dark  brown,  showing  thru  the  walls  of  the 
distended  uterus-sacs. 

Habitat:  Intestine  and  pyloric  coeca  of  the  "rock  cod, "  Sebastodes  sp. 

Type  specimen:  No.  4740  in  the  collection  of  the  United  States  Museum, 
collected  by  T.  H.  Bean  and  identified  by  Professor  Edwin  Linton. 

Tj^e  locality:  Whatcomb,  Washington. 

The  material  contained  in  lot  No.  4740  of  the  coUection  of  the  United 
States  Museum,  upon  which  Linton  based  his  species,  was  examined  by  the 
writer  and  confirmatory  sections  were  made  of  mature  segments;  but  it  was  all 
in  such  a  very  poor  state  of  preservation  that  only  a  httle  can  be  added  to  the 
meagre  descriptions  already  published. 


ISO  ILUNOIS  BIOLOGICAL  MONOGRAPHS  [438 

Liihe  (1899:43)  stated  under  his  diagnosis  of  the  genus  that  "Von  weniger 
gut  bekannten  Arten  gehoren  auscheinend  noch  hierher  Bothriocephalus  lacinion 
tus  (Lint.)  und  occidentalis  (Lint.),"  "while  Ariola  (1900:415)  included  it  in  his 
compendium  of  the  kno-wm  species. 

Since  no  scolex  and  only  very  poorly  preserved  anterior  parts  of  the  stro- 
bila  were  found  in  the  above  mentioned  lot,  Linton's  description  is  here  given 
verbatim: 

"The  bottle  contained  two  fragments  and  portion  of  pyloric  coeca  of  fish. 
The  fragments  measured  190  and  310mm.  in  length,  respectively.  Another 
fragment  with  scolex  was  found  in  one  of  the  pyloric  coeca;  this  was  115mm. 
in  length. 

Head  small,  elongated  trimcate,  and  somewhat  capitate,  constricted  near 
posterior  end  with  prominent  posterior  margin;  fossettes  coincide  ^vith  flat  sur- 
face of  body  and  extend  posteriorly  nearly  to  constriction;  segments  begin 
immediately  behind  head,  somewhat  funnel-shaped,  soon  becoming  densely 
crowded  and  much  broader,  ten  to  twenty  or  more  times  as  broad  as  long, 
decreasing  in  breadth  and  increasing  in  length  again  toward  posterior  end. 
Posterior  segments  in  groups  of  three  or  four,  namely,  divisions  between  seg- 
ments of  contiguous  groups  more  distinctly  marked  than  between  other  adjacent 
segments. 

Dimensions  of  head  and  segments:  Length  of  head,  1.30mm.;  breadth 
of  head,  apex,  0.46;  middle,  0.46;  base,  0.40;  breadth  of  first  segment,  0.42; 
length  of  first  segment,  0.12;  greatest  breadth,  5.5;  length  of  broadest  segments, 
0.25 ;  breadth  of  posterior  end,  2 ;  length  of  posterior  segments,  0.8.  .  .  . 

The  sides  of  the  head  which  correspond  with  the  lateral  margins  of  the  body 
are  medianly  depressed  toward  anterior  end. " 

Concerning  the  cuticula  nothing  more  can  be  said  than  that  in  the  anterior 
segments  where  it  did  not  seem  to  be  much  eroded,  it  was  found  to  be  only 
about  1.5m  in  thickness.  The  subcuticular  cells  are  closely  crowded  together. 
They  form  a  syncitioid  layer,  in  which  the  comparatively  large  nuclei  (8)u  in 
diameter)  stand  out  prominently,  beginning  about  35/i  from  the  surface  and 
extending  centrally  to  the  vitelline  glands.  As  pointed  out  by  Linton,  "Cal- 
careous bodies  are  present  in  the  central  core  [medulla]  and  sparsely  scattered 
elsewhere,  but  nowhere  abundant.  .  .  "  The  largest  of  them  were  found 
to  be  18ai  long  by  13  wide,  thus  being  within  the  limits  of  measurements  of 
those  of  B.  manuhriformis. 

In  general  the  musculature  is  quite  comparable  to  that  of  B.  manuhriformis. 
There  is  a  stratiun  of  frontal  fibres  on  each  surface  of  the  layer  of  longitudinal 
fibres,  but  no  third  or  outermost  group  in  the  anterior  segments,  doubtless 
owing  to  the  fact  that  the  posterior  borders  of  the  latter  are  not  nearly  so 
prominent.  Both  layers  are  related  to  the  uteri  and  cirrus-sacs  in  the  same 
way.  The  sagittal  fibres  are  much  less  numerous  especially  anteriorly.  While 
the  main  longitudinal  muscles,  arranged  in  quite  the  same  manner  and  with 
the  same  thickness,  namely,  145/i,  render  the  cross-section  of  mature  segments 
similar  to  that  of  B.  manubriformis  at  first  sight,  the  fibres  of  the  external  group 


439)  PSEU DOPEY LLIDEA  FROM  FISHES— COOPER  151 

of  this  series  are  very  scarce,  confined  to  the  anterior  segments  and  very  difficult 
to  distinguish  from  the  longitudinal  cuticular  fibres. 

The  nerve  strands,  each  about  35/*  in  transverse  diameter  anteriorly  and 
85/i  thick  by  45)li  wide  in  mature  segments,  are  situated  between  the  lateral 
and  median  quarters  of  the  transverse  diameter  of  the  strobila.  Unlike  con- 
ditions in  the  foregoing  species,  they  occupy  either  the  whole  of  the  dorsoventral 
diameter  of  the  medulla  or  are  situated  strictly  in  the  median  frontal  plane, 
depending  on  the  degree  of  lateral  contraction. 

In  the  anterior  segments  two  main  longitudinal  excretory  vessels  are  located 
in  the  meduUa  between  the  nerve  strands;  while  two  others,  much  smaller  and 
outside  of  the  latter,  are  somewhat  difficult  to  follow.  In  mature  proglottides, 
however,  all  four  vessels  are  fairly  easily  distinguished,  especially  in  transec- 
tions. 

"The  cirrus  and  vagina  open  by  a  common  aperture  on  the  middle  of  one 
of  the  flat  surfaces  of  the  body.  .  .  .  The  vagina  is  behind  the  cirrus;  in 
some  cases  directly  behind  it,  in  others  a  little  to  one  side  or  other  of  the  median 
line. "  This  was  found  to  be  in  the  main  true,  altho  on  close  examination  it 
is  to  be  seen  that  the  common  genital  openings  form  a  zig-zag  row  as  in  the 
foregoing  species.  The  uterus-openings,  described  as  opening  "externally 
on  the  middle  of  the  dorsal  surface, "  likewise  alternate  irregularly  from  side 
to  side.  Furthermore,  while  the  genital  cloaca  is  situated  at  the  middle  of  the 
very  short  proglottis,  the  opening  of  the  uterus -sac  is  in  the  anterior  portion 
of  the  segment,  often  being  under  the  posterior  border  of  the  segment  ahead. 
The  cloaca  itself  is  very  shallow  in  this  species,  the  openings  of  the  cirrus  and 
vagina  being  almost  at  the  surface.  There  is  no  definite  velum  separating 
an  inner  ductus  hermaphroditicusfrom  an  outer  cloaca  as  in  B.  manuhriformis. 

In  the  sections  made,  the  testes,  divided  into  two  fields  on  each  side  by 
the  nerve  strand,  were  much  compressed  anteroposteriorly  with  average  maxi- 
mum lengths,  breadths  and  depths  of  25,  85  and  115/i,  respectively.  On  ac- 
count of  this  crowded  condition  it  was  not  found  practicable  to  count  their 
number  directly  in  frontal  sections,  but  it  was  calculated  to  be  from  75  to  90. 
The  vas  deferens,  averaging  about  25/i  in  diameter,  forms  a  number  of 
loose,  open  coils  extending  thruout  the  whole  dorsoventral  diameter  of  the 
medulla  on  the  side  towards  which  the  central  end  of  the  cirrus-sac  is  directed, 
and  alternating  irregularly  from  side  to  side  as  does  the  uterus-sac,  but  being 
constantly  located  on  the  opposite  side  of  the  median  line  from  the  latter. 
As  it  passes  into  the  base  of  the  cirrus  pouch  it  has  a  diameter  of  only  3/i. 
In  the  proximal  or  central  one-third  of  the  sac  it  takes  a  few  turns  and  then 
continues  as  a  straight  tube,  somewhat  larger  (IS/i)  and  usually  filled  with 
spermatozoa,  the  functional  cirrus  which  is  about  8)u  in  diameter.  The  cirrus- 
sac  is  elongate  oval  to  cylindrical  in  shape,  the  slightly  larger  end  is  ventral, 
and  has  a  maximum  length  and  a  diameter  of  230  and  60/li,  respectively.  It 
is  thus  approximately  only  one-half  as  large  as  that  of  B.  manubriformis;  nor 
does  it  extend  ventrally  past  the  lower  edge  of  the  layer  of  main  longitudinal 
muscles.    Its  wall,  as  shown  in  figure  89,  is  comparatively  thin,  as  pointed  out 


152  ILLINOIS  BIOLOGICAL  MONOGRAPHS  [440 

by  Linton,  especially  in  the  dorsal  half,  the  inner  layer  of  circular  fibres  being 
much  more  numerous  ventrally.  Thus  there  is  left  a  comparatively  large 
space  aroimd  the  ejaculatory  duct  to  accommodate  the  retractor  muslces 
and  a  small  amount  of  parenchyma  the  nuclei  of  which  are  situated  peripherally 
much  as  in  B.  scorpii.  A  character  which  distinguishes  this  species,  however, 
from  others  of  the  genus  is  the  presence  of  a  loosely  arranged  bundle  of  muscle - 
fibres  attached  to  the  ventral  end  of  the  cirrus-sac  and  passing  downwards  be- 
tween the  coils  of  the  uterine  duct,  beyond  which  they  do  not  seem  to  have  any 
definite  attachment.  Since  the  myoblasts  and  nuclei  of  these  fibres  are  quite 
prominent,  especially  some  distance  from  the  cirrus-sac,  the  whole  bundle 
has  something  of  the  appearance  of  an  elongated  gland.  The  protruded  cirrus 
has  a  maximum  length  of  SS/x  with  a  diameter  of  30/i.  This  everted  condition 
of  the  cirrus,  taken  in  conjunction  with  the  nature  of  the  genital  cloaca  de- 
scribed above,  and  the  fact  that  there  is  no  vaginal  sphincter,  points  strongly 
to  the  cross-fertilization  of  at  least  different  proglottides,  rather  than  to  self- 
fertihzation.  The  former  would,  furthermore,  seem  possible  between  con- 
tiguous segments,  since  in  many  cases  two  consecutive  cloacae  were  found  close 
together  and  at  the  bottom  of  an  apparently  temp>orary  depression  of  the  dorsal 
s\irface. 

The  vagina  has  no  sphincter,  but  begins  somewhat  broadly,  as  shown  in 
Linton's  figure  5,  only  to  narrow  down  quickly  to  about  5/i  half  way  along  its 
course,  which  is  almost  straight  ventrally.  It  expands  slightly  before  joining 
the  oviduct  but  does  not  form  more  than  a  temporarily  functional  seminal 
receptacle.  The  ovar}%  much  compressed  anteroposterior^,  is  from  0.5  to 
0.6nmi.  wide  by  only  40/x  long  at  the  isthmus,  and  from  0.13  to  0.18mm.  deep. 
Its  limbs  are  entire  but  much  disturbed  in  their  course  laterally  by  the  uterine 
ducts  of  contiguous  proglottides.  The  oocapt  has  an  average  diameter  of 
25//.  Beyond  it  the  oviduct  enlarges,  after  constricting  as  usual,  to  about 
25m  again  where  it  is  joined  by  the  vagina.  At  the  latter  point  there  is  a  vesti- 
bule as  in  the  last  species.  Just  beyond  this  the  oviduct  is  joined  by  the  com- 
mon vitelline  duct  which  is  enlarged  near  the  jimction  to  form  the  yolk  reservoir 
or  "central  vitelline  mass,"  about  45/i  in  diameter.  The  vitelline  follicles 
are  very  numerous  and  closely  arranged  in  the  cortex  in  two  lateral  fields,  leav- 
ing a  broad  median  strip  free  of  them  on  each  surface  of  the  strobila.  Their 
maximum  lengths,  breadths  and  depths  are  25,  60  and  115m  respectively; 
they  have  thus  approximately  the  same  bulk  individually  as  those  of  B.  manu- 
briformis.  They  are  continuous  at  the  edges  of  the  strobila  and  occupy  the 
central  one-half  of  the  thickness  of  the  cortical  parenchyma,  excepting  in  the 
median  free  strips.  While  the  rather  small  shell-gland  occupies  a  somewhat 
limited  position  dorsally  at  the  level  of  the  ventral  end  of  the  cirrus-pouch, 
the  uterine  duct  takes  so  many  coils,  all  of  which  are  filled  with  eggs,  in  the 
median  portion  of  the  proglottis  on  both  sides  of  the  midline  that  most  of  the 
other  structures  are  all  but  obUterated — at  least  at  first  sight.  Both  the  uter- 
ine duct  and  the  uterus-sac  are  arranged  pretty  much  as  in  B.manubrifarmis; 
but  the  latter  is  only  from  0.27  to  0.37mm.  wide  by  about  0.15  long  and  about 


441]  PSEUDOPHYLLIDEA  FROM  FISHES— COOPER  153 

0.35  deep  in  proglottides  where  the  whole  median  portion  is  gorged  with  eggs. 
In  the  widest  segments,  however,  they  may  attain  a  width  of  0.65mm.  by  a 
length  of  0.25  but  at  the  same  time  not  encroach  so  much  on  the  neighboring 
segments  as  in  the  last  species;  for  the  length  of  the  broadest  segments,  as 
given  above,  is  0.25mm.  The  lower  portion  of  the  sac  is  not  modified  into  a 
funnel-shaped  structure,  while  the  actual  opening  is  only  about  15)u  in  diameter. 

The  measurements  of  the  eggs  are,  according  to  Linton,  72  to  76^t  in  length 
by  38  to  41  in  breadth.  Such  were  found  in  the  sections  made,  but  no  opercula 
such  as  shown  in  his  figure  11 ;  altho  many  similar  appearances  were  considered 
to  be  only  regular  breaks  in  the  shell. 

From  the  above  description  it  is  to  be  seen  that  in  many  respects  this 
species  is  very  close  to  B.  manuhriformis.  But  in  others  it  is  sufficiently 
diflFerent  to  warrant  the  retention  of  Linton's  designation,  the  more  so  in  view 
of  the  fact  that  the  host  was  taken  from  the  Pacific  coast,  the  bothriocephalid 
fauna  of  which  has  apparently  not  yet  been  touched. 

CLESTOBOTHRIUM  Liihe  1899 


Bothriocephalus  (part.) 

Rudolphi 

1819 

Dibothrius  (part.) 

Rudolphi 

1819 

Bothriocephalus  (part.) 

Leuckart 

1819 

Bothriocephalus  (part.) 

Dujardin 

1845 

Dibothrium  (part.) 

Diesing 

1850 

Dibothrium  (part.) 

Molin 

1858 

Dibothrium  (part.) 

Diesing 

1863 

Bothriocephalus  (part.) 

Cams 

1885 

Bothriocephalus  (part.) 

Ariola 

1896 

Clestobothrium 

Liihe 

1899 

Bothriocephalus  (part.) 

Ariola 

1900 

Clestobothrium 

Braun 

1900 

Scolex  almost  spherical,  the  free  edges  of  the  dorsoventrally  situated 
bothria  fused  with  each  other  in  their  whole  extent  in  such  a  manner  that  only 
a  small  surficial  opening  near  the  apex  leads  into  the  interior  of  the  spacious, 
hollow  organ  of  attachment,  flattened  in  the  sagittal  direction,  by  means  of 
a  short  almost  sagitally  coursing  canal  which  can  be  closed  by  a  sphincter-like 
musculature.  External  segmentation  complete.  Vitelline  foUicles  in  the 
cortical  parenchyma.  Receptaculum  seminis  small.  Beginning  of  the  uterus 
a  winding  canal  which  leads  into  an  extraordinarily  spacious  uterus-sac,  dis- 
torting all  other  genital  organs  in  ripe  proglottides.  Uterine  opening  about 
median  as  is  the  dorsal  genital  opening. 

Type  and  only  species:  C.  crassiceps  (Rudolphi). 


154  ILLINOIS  BIOLOGICAL  MONOGRAPHS  (442 

CLESTOBOTHRIUIVI  CRASSICEPS  (Rudolphi  1819) 
[Figs.  29-31,  48,  49,  58,  74,  75,  90,  103,  108] 


1819 

Bolhriocephalus  crassiceps 

Rudolphi 

1819 

:  139,  476 

1819 

Bothriocephalus  pilula 

Leuckart 

1819 

:45 

1845 

Bolhriocephalus  crassiceps 

Dujardin 

1845 

:617 

1850 

Diboihrium  crassiceps 

Diesing 

1850 

:587 

1858 

Dibothrium  crassiceps 

Molin 

1858 

:134 

1863 

Dibothrium  crassiceps 

Diesing 

1863 

:236 

1885 

Bothriocephaltis  crassiceps 

Cams 

1885 

:120 

1896 

Bothriocephalus  crassiceps 

Ariola 

1896 

:280 

1899 

Clestobothrium  crassiceps 

Liihe 

1899 

:44 

1900 

Bothriocephalus  crassiceps 

Ariola 

1900 

:397 

1900 

Clestobothrium  crassiceps 

Braun 

1900 

:1692 

1901 

Dibothrium  crassiceps 

Linton 

1901 

:411,  451,  473 

1909        Dibothrium  crassiceps  Johnstone  1909  :  87 

Specific  diagnosis:  With  the  characters  of  the  genus.  Medium  sized  ces- 
todes,  up  to  92mm.  in  length,  with  a  maximum  breadth  of  1.5mm.  Anteriorly 
surface  of  body  with  closely  arranged  transverse  furrows,  posteriorly  segmenta- 
tion more  distict,  serrate.  Scolex  globose,  0.64  to  1.08mm.  long,  0.52  to  0.90 
broad,  and  0.68  to  1.21  thick;  divided  by  longitudinal  marginal  grooves  into 
two  dorsoventral  hemispheres,  the  bothria.  Latter  large,  prominent,  oval, 
their  apertures  about  one-third  their  length  from  the  apex  and  connected  by  a 
saddle-shaped  groove  over  the  tip  of  the  scolex,  with  prominent  lips.  No  neck, 
segmentation  beginning  immediately  behind  the  scolex.  Young  segments 
closely  arranged,  five  to  six  times  as  broad  as  long;  mature  proglottides  quad- 
rate to  twice  as  long  as  broad,  frequently  divided  on  one  or  both  sides  by 
spurious  articulations  usually  behind  the  uterus-sacs. 

Cuticula  2  to  5n  thick,  subcuticula  20ijl.  Chalk-bodies  absent.  Muscula- 
ture well  developed,  powerful  sphincter  around  orifice  of  bothrium.  Chief 
nerve  strands  ventral,  15  to  20/li  in  diameter.  Usually  four  longitudinal  ex- 
cretory vessels. 

Genital  cloaca  median,  dorsal,  three-fourths  to  one-half  the  length  of  the 
proglottis  from  its  anterior  end,  usually  just  posterior  to  the  spurious  articula- 
tions; hermaphroditic  duct  within  cloaca. 

Testes  in  two  lateral  fields  in  the  medulla;  ellipsoidal  in  shape,  0.125mm. 
long  by  0.04  in  diameter,  continuous  from  joint  to  joint,  40  to  50  in  each  proglot- 
tis. Vas  deferens  forms  a  wedge-shaped  mass  of  coils  ahead  of  cirrus-sac  and 
alongside  of  the  hinder  end  of  the  uterus-sac.  Cirrus-sac  elliptical  to  some- 
what oval,  0.128  to  0.162mm.  long  by  0.087  to  0.116  wide  and  0.098  to  0.116 
deep,  immediately  behind  the  uterus-sac  or  lateral  to  its  posterior  end.  Cirrus- 
sac  and  vas  deferens  together  alternate  irregularly  from  right  to  left  opposite 
the  hinder  end  of  the  uterus-sac. 

Opening  of  vagina  close  behind  that  of  cirrus.  Receptaculum  seminis 
present  as  a  short  diverticulum  almost  parallel  to  the  oviduct  at  the  point  of 
union  of  the  vagina  with  the  latter,  about  lOjn  in  diameter.  Ovary  bilobed, 
the  isthmus  narrow  and  ventral,  ova  in  same  18  by  10^.    Oocapt  20/x  in  dia- 


4431 


PSEUDOPHYLLIDEA  FROM  FISHES-COOPER 


155 


meter.  Vestibule  at  the  point  of  union  of  the  vagina  with  the  oviduct.  Vitel- 
Une  duct  expands  into  a  reservoir  30^1  in  diameter.  Vitelline  follicles  not  in 
lateral  fields,  but  continuous  from  joint  to  joint,  60  by  30  by  50/i  in  dimensions, 
about  700  in  each  proglottis.  Uterus-sac  elliptical  in  outline,  directed  antero- 
posteriorly  in  the  anterior  half  of  the  proglottis,  where  in  gravid  segments  it 
occupies  almost  the  whole  of  the  medullary  region;  2.20  by  1.34mm.  in  dimen- 
sions; in  quadrate  segments  irregularly  alternating  from  side  to  side  as  are  the 
uterine  openings. 

Eggs,  75  by  40/i. 

Habitat:  In  the  anterior  portion  of  the  intestine  of  the  host. 


HOST 

LOCALITY 

COLLECTOR 

AUTHORITY 

Gadus  merluccius 

Naples 

Rudolphi 

Rudolphi 

1819  :  139 

(Type  host) 

Cddus  tnerluccius 

Leuckart 

Leuckart 

1819  :  45 

Cadus  merluccius 

Patavia 

Molin 

Molin 

1858  :  134 

Gadus  merluccius 

Trieste 

Stossich 

Cams 

1885  :  120 

Gadus  euxinus 

Trieste 

Stossich 

Stossich 

1899  :1 

Merlangus  carhonarius 

NizzA 

Wagener 

Wagener 

1854  :  61 

Merlangus  sp. 
Merluccius  bilinearis 

Wagener 
Linton 

Wagener 
Linton 

1857  :  93 

Woods  Hole 

1901  :  473 

Merluccius  esculentus 

Parona 

Ariola 

1896  :  265 

Merluccius  esculentus 

Trieste 

Stossich 

Stossich 

1898  :  115 

Merluccius  merluccius 

Pisa 

Wagener 

W^agener 

1854  :  68 

Merluccius  vulgaris 

Ireland 

Drummond 

Thompson 

1844  :  439 

Merluccius  vulgaris 

Patavia 

Molin 

Molin 

1861  :  235 

Merluccius  vulgaris 

Pisa 

Wagener 

Diesing 

1863  :  237 

Merluccius  vulgaris 

Padova 

Molin 

Diesing 

1863  :  237 

Merluccius  vulgaris 

Genova 

Parona 

Ariola 

1896  :  265 

Merluccius  vulgaris 

Portaferrajo, 
Id.  Elba 

Damiani 

Parona 

1899  : 8 

Merluccius  vulgaris 

Pisa 

Parona 

Parona 

1899  :8 

Merluccius  vulgaris 

Gaeta 

Ariola 

Ariola 

1900  :  397 

Merluccius  vidgaris 

Augusta, 

Barbagallo  and 

Barbagallo 

1903  :  412 

Catania 

Drago 

and  Drago 

Pomalomus  saltatrix 

Woods  Hole 

Linton 

Linton 

1901  :  451 

"A  small  hake" 

Calf  of  Man, 
England 

Johnstone 

Johnstone 

1909  :  87 

Merluccius  bilinearis 

Passamaquoddy 

Cooper 

Cooper 

Bay,  St.  Andrews, 

(the  present  paper) 

N.B. 

Merluccius  hilinearis 

Buzzards  Bay, 
Mass. 

Cooper 

>i 

Merluccius  bilinearis 

Vineyard  Sound, 
Mass. 

Cooper 

i> 

Merluccius  bilinearis 

Casco  Bay,  Me. 
South  Harpswell 

Cooper 

»» 

156  ILUNOIS  BIOLOGICAL  MONOGRAPHS  [44  4 

In  external  appearance  this  species  is  characterized  by  the  globose  nature 
of  the  scolex  and  the  serrate  margins  of  the  strobila,  the  former  of  which  was 
the  basis  of  Leuckart's  (1819:45)  speciJ&c  name  and  which  with  the  latter  was 
emphasized  and  included  in  the  diagnoses  given  by  all  the  authors  after  Rudol- 
phi  (1819).  But  another  important  character  which  also  assists  in  the  ready 
recognition  of  the  species  is  the  presence  of  spurious  articulations,  which,  how- 
ever, are  evidently  not  those  mentioned  collectively  by  Wagener  (1854:69)  as 
"articulatio  spuria." 

The  scolex  (Figs.  29-31)  is  divided  by  two  longitudinal  marginal  grooves 
into  two  dorsoventral  hemispheres,  the  bothria.    The  latter  were  considered 
by  Rudolphi  (1819:130,  477)  and  others  to  be  marginal  in  position,  but  many 
years  elapsed  before  this  error  was  finally  and  definitely  corrected  by  Liihe 
(1899:35).   F.  S.  Leuckart  (1819:45)  rightly  described  and  figured  the  scolex  as 
"medio  marginali  sulcato,  foveis  lateralibus.  ..."  and  "Die  Randflache 
des  Kopfes  ist  breiter  als  die  Seitenflache,  die  mittelfurche  jener  ziemlich  tief, 
und  bi  det  an  jener  Seite  eine  erhabene,  in  der  Mitte  hellere  Wolbung. "  It  seems 
that  Molin  (1881:235)  fell  into  the  error  of  considering  the  marginal  or  lateral 
grooves,  separating  the  bothria,  to  be  the  bothria  themselves,  as  indicated  in 
his  diagnosis:    "Caput  magnum  subglobosum,  utrinque  sulco  longitudinaU 
lateraU,  apertura  centrali  bUabiata  antica,  bothriis  ovaUbus,  subter  min- 
aUbus,  marginahbus,  longis";  and  in  his  "Osservazione  2"  he  said:  "Quan- 
timque  la  testa  sia  molta  grossa  ed  opaca,  ci6  non  per  tanto  potei  distinguere 
il  solco  menzionato  da  Diesing  [1850:587]  il  quale  pero  corrisponde  ai  lati 
e  non  ai  margini  del  corpo,  e  sembra  dividere  la  testa  in  due  emisferi.    Ognuno 
di  questi  porta  ima  fossetta  oblunga,  ovale,  che  si  estende  dall'  apice  a  due  terzi 
della  lunghezza  del  corpo,  e  sembra  di  quattro  quadranti  suddivisi  da  due  solchi 
che  s'incrocciano. "    It  is  evident  from  his  figure  2,  Taf.  V,  that  the  "fossetta 
oblunga"  is  the  entrance  to  the  bothrium,  but  he  does  not  seem  to  have 
observed  the  actual  opening.    Matz  (1892:103)  expressed  the  opinion  that  the 
bothria  of  this  species  are  dorsoventral  in  position,  while  Ariola  (1896:280)  evi- 
dently on  the  basis  of  former  descriptions  placed  the  species  among  those  of 
the  genus  Bothriocephalus  Rud.  with  "Botridi  marginali."    Stossich  (1898: 
115)  also  described  the  scolex  as  "   ...  subglobosa,  con  botridii  marginali, 
subterminah,  ovato-allungati. "    Ariola  (1900:398)  finally  corrected  his  own 
view  of  the  external  structure  of  the  scolex  by  saying  that  "  Un  esame  anche 
superficiale  dimostra  pero  che  la  posizione  degli  organi  di  fissazione  non  e  equale 
fu  ritenuta,  perche  ciascun  d'essi  corrisponde  ad  una  faccia  larga  dello  strobila,  o 
como  si  dice,  sono  dorsoventrali.    I  pretesi  botridii  marginali  sono  dati  da  im 
solco  circulare,  abbastanza  profondo,  che  corre  a  guisa  di  un  meridiano  attomo 
alio  scolice  globoso,  passando  per  I'apice,  e  dividuendolo  come  in  due  emisferi, 
imo  destro  a  I'altro  sinistro, "  thus  evidently  ignoring  the  fact  that  Liihe  had 
already  (1899:25)  performed  the  service  for  students  of  the  group,  as  he  later 
pointed  out  with  justifiable  emphasis  (Liihe,  1901:414). 

The  bothria  in  this  species  are  sac-like  structures,  formed  (phylogenetically) 
as  indicated  in  the  generic  diagnosis,  by  the  rolling  together  of  their  edges  or 


445)  PSEUDOPHYLUDEA  FROM  FISHES— COOPER  157 

"walls"  and  the  fusion  of  the  latter  for  most  of  their  extent  "in  such  a  manner 
that  only  a  small  lateral  [dorsoventral]  opening  in  the  region  of  the  apex 
leads  into  the  anterior  of  the  spacious,  hollow  organ  of  attachment. "    The 
size  and  shape  of  the  opening  itself  varies  considerably  in  preserved  material. 
It  may  be  so  small  (Fig.  29)  as  to  be  seen  only  on  very  close  examination  or  in 
sections,  or  comparatively  large  (Fig.  49),  depending  on  the  stage  of  contrac- 
tion or  enlargement  of  the  bothria  when  the  individual  is  fixed  or  preserved. 
During  life  it  may  be  seen  to  undergo  such  variations  in  size  while  the  whole 
scolex  isbeing  elongated  and  retracted  during  the  characteristic  sucking  move- 
ments.    Rudolphi  (18 19:47  7)  correctly  described  the  bothria  as".  .  .  oblonga 
profunda  et  magna  in  vivis;  in  mortuis  bothrii  ostium  parvimi  anticum  adesse 
videtur."    In  lateral  view  (Fig.  30)  the  bothria  are  seen  to  be  more  sharply 
oval  or  even  conical  in  outline,  as  is  consequently  the  whole  scolex,  owing  to 
the  fact  that  the  dorsoventral  diameter  of  the  lumen  of  each  is  much  greater 
in  its  posterior  half  than  in  its  anterior  half.    It  will  also  be  noted  more  clearly 
from  this  aspect  that  the  hinder  borders  of  the  bothria  project  a  considerable 
distance  beyond  the  true  anterior  end  of  the  strobila.    Thus  the  length  of  the 
scolex  is  not  that  of  the  bothrium,  as  many  \\Titers  have  evidently  taken  it  to 
be,  but  as  far  as  can  be  determined  from  external  views,  more  nearly  that  of 
the  marginal  sulcus  plus  an  extension  of  the  same  to  the  tip  of  the  scolex,  or, 
where  the  latter  is  retracted,  to  the  anterior  border  of  the  labia.    The  breadth 
of  the  scolex  is  here  taken  for  the  sake  of  convenience  to  be  that  of  the  bothrium, 
since  there  is  very  little  difference  betv/een  the  two  in  this  regard.    The  two 
apertures  of  the  bothria  are  united  over  the  tip  of  the  scolex  by  a  saddle-shaped 
groove,  the  edges  of  which  are  somewhat  swollen  so  as  to  form  lip-like  struc- 
tiures.    This  groove  has  been  described  and  figured  for  C.  eras  sleeps  by  Molin 
(1861:235,  Fig.  2,  Tab.  V)  and  Ariola  (1900:397,  Fig.  17,  Taf.  VIII)  and 
figured  by  Linton  (1901a :Fig.  267,  PI.  24),  but  it  does  not  appear  either  in  the 
figures  given  by  Wagener  (1854 :Fig.  75,  Taf.  7;  1857  :Fig.  6,  PI.  II)  or  that  by 
Johnstone  (1909 :87,  Fig.  14).   It  is  present  in  all  of  the  writer's  material  even  to 
the  youngest,  but  in  a  few  cases  the  tip  of  the  groove,  that  is  the  extreme  tip 
of  the  scolex,  is  so  prominent  as  to  more  or  less  obliterate  the  lips  (Fig.  49).    It 
is  also  to  be  noted  that  the  lateral  grooves  separating  the  bothria  do  not  pass 
thru  these  lips.    This  is  nicely  indicated  in  Ariola's  figure  but  erroneously 
described  by  him  as  "passando  per  I'apice, "  and  as  further  figured  but  in 
the  same  relation  by  Johnstone.    Wagener's  figiire  75  and  Linton's  figure  266 
also  give  the  erroneous  impression  that  this  groove  passes  right  over  the  tip 
of  the  scolex.    Molin  (1861:235),  while  giving  a  somewhat  confused  descrip- 
tion of  the  relations  between  the  saddle-shaped  structures — which  he  figures 
as  including  the  apertures  of  the  bothria  more  posteriorly — and  the  lateral 
grooves,  says  that  he  saw  in  the  apex  an  aperture  which  not  only  ended  blindly 
but  which  was  bounded  by  two  eminences,  simulating  lips.    This  may  have 
been  due  to  extreme  contraction  of  the  tip  of  the  scolex  between  the  lips  of  this 
groove.    It  will  be  recalled  that  Leuckart  (1819:46)  stated  in  this  connection 
that  "An  dem  Kopfende  ist  eine  kleine  Vertiefung  in  der  Mitte;  die  von  den 


158  ILLINOIS  BIOLOGICAL  MONOGRAPHS  [446 

beiden  sich  hier  vereinigenden  Randfurchen  herriilirt,  wodurch  ihre  Rander 
etwas  erhabener  werden.  Die  Griibchen  sind  kaum  von  der  Grosse  eines 
Nadelknopfchens  und  tief  in  Kopfe,  so  dass  es  fast  scheinen  konnte,  als  waren 
sie  wahre  oscula;"  but  his  figure  26,  very  good  in  other  respects,  does  not  do 
justice  to  his  description  of  these  terminal  structures.  Compare  also  Lonn- 
berg's  (1893:  15-17)  B.  neglectus,  the  figure  for  the  scolex  of  which  looks  very 
much  like  B.  crassiceps. 

There  is  no  neck  in  this  species,  but  segmentation  begins  immediately  behind 
the  scolex  (Fig.  48)  and  is  complete  thruout  the  strobila.  These  characters 
were  included  by  Liihe  (1899:44)  in  the  diagnosis  of  the  genus:  "Aussere 
Gliederung  vollkommen,  ein  gegliederter  Hals  fehlt. "  As  regards  this  quo- 
tation, it  would  appear  that  the  "  gegUederter  "  is  either  superfluous  or  a  lapsus 
calami  for  "  imgegliederter. "  The  anterior  border  of  the  first  segment,  a 
greater  part  of  which  is  obscured  by  the  hinder  edges  of  the  bothria,  is  con- 
stantly somewhat  narrower  than  the  latter,  but  its  posterior  border  is  usually 
about  the  same  width  even  in  such  contracted  specimens  (Fig.  29).  Its  out- 
line is  somewhat  trapezoidal,  while  its  length  is  slightly  greater  than  that  of 
the  segment  immediately  following.  The  breadth  of  this  first  segment  varies 
anteriorly  from  0.40  to  0.92mm.  and  posteriorly  from  0.65  to  1.16 — Linton's 
measurements  are  0.78  and  1.07,  respectively.  Following  this  the  segments 
are  closely  set,  five  to  six  times  as  broad  as  long,  while  their  somewhat  thickened 
posterior  borders  protrude  on  either  side  (as  well  as  dorsoventrally)  so  as  to  give 
the  strobila  a  serrate  appearance  (Fig.  48).  It  is  here  that  the  formation  of 
new  proglottides  takes  place  by  the  subdivision  of  preexisting  segments.  This 
serrate  appearance  is  also  present  in  the  posterior  part  of  the  strobila,  where 
the  proglottides  are  quadrate  to  twice  as  long  as  broad. 

Posteriorly  each  serration  does  not  necessarily  define  the  posterior  border 
of  a  proglottis.  This  is  due  to  the  presence  of  spurious  articulations,  possibly 
included  in  Wagener's  "articulatio  spuria."  These  are  furrows  which  arise 
laterally,  where  they  do  not  stand  out  as  distinctly,  however,  as  the  true  pos- 
terior borders  of  the  proglottides,  but  do  not  pass  to  the  median  Une.  They 
are  not  present  in  aU  of  the  posterior  proglottides  nor  are  they  symmetrically 
arranged.  In  the  following  excerpt  from  his  more  complete  diagnosis  it  is 
to  be  seen  that  Rudolphi  (1819:477)  did  not  refer  to  these  structures: 

"Articuli  breves,  margine  posteriore  incrassato  utrinque  exstante,  quo 
corpus  serratum  fiat.  Articuli  ceterum  inaequales,  ut  passim  augustiores  et 
longiores  intercurrant. "  F.  S.  Leuckart  said  only,  "Die  ersten  Glieder 
am  Kopfe  schmaler  als  die  tjbrigen,  dann  folgen  fast  gleichbreite, 
die  letzte  Halfte  der  Glieder  breiter  als  lang,  mit  deutlichen,  weissen 
Ovarien,"  which  statement  refers  to  "der  beschreibene  nicht  ganze  Wurm 
.  .  .  13^"  lang."  Diesing  (1863:236)  described  the  strobila  as  "  .  .  .  el- 
lipticum,  articuHs  ad  medium  usque  increscentibus,  inde  descrescentibus, 
maxginaUbus  posticis  utrinque  prominentibus,  articulo  singulo  pUca  transver- 
saH  diviso  ..."  The  latter  has  reference  obviously  to  Wagener's  "  articulo 
spuria."    It  is  also  seen  that,  as  regards  the  shape  of  the  strobila,   he 


447]  PSEUDOPHYLLIDEA  FROM  FISHES— COOPER  159 

(Diesing)  was  dealing  with  much  contracted  specimens,  the  length  being  cited 
as  ranging  from  one  and  a  half  lines  to  two  inches.  Ariola  (1900:397)  gave  the 
following  description  of  the  segments: 

"Strobila  anteriormente  assai  piu  stretto  dello  scolice,  a  guisa  di  peduncolo; 
le  primi  proglottidi  sono  rettangulari,  strette,  ma  rapidamente  si  allargano; 
raggiunta  la  massima  dimensione,  la  conservano  sino  all  ultimo  tratto  del 
corpo,  dove  nuovamente  si  restringono.  Le  proglottidi  mature  hanno  angula 
posteriori  appena  visibili;  le  ultime  presentano  forma  trapezoidale. "  And 
Johnstone  (1909:89)  stated,  "The  posterior  proglottides  are  much  broader 
(in  the  transverse  axis  of  the  strobila)  than  they  are  long  (in  the  longitudinal 
axis  of  the  strobila) ;  and  their  anterior  extremities  are  narrower  than  the  pos- 
terior ones,  so  that  the  edge  of  the  strobila  appears  to  be  serrated.  Secondary- 
segmentation  of  the  proglottis  often  occurs. " 

In  fine,  Wagener,  Diesing,  and  Johnstone  are,  to  the  writer's  knowledge, 
the  only  writers  who  have  referred  to  this  spurious  articulation  or  subdivision 
of  the  segments  into  false  secondary  segments — although  Liihe  (1902:629) 
repeated  the  statements  of  the  first  two  authors.  Furthermore,  Wagener 
did  not  figure  the  adult  strobila  of  the  species  to  show  the  structures  in  ques- 
tion, but  in  the  legend  for  his  figure  79,  Taf.  7  of  Dibothrium  heteropleurum, — 
now  Amphicotyle  heteropleura  (Diesing) — says  only  that  "Man  sieht  die 
articulo  spurio,  welche  die  echten  Glieder,  wie  bei  Dibothrium  crassiceps,  in 
der  Mitte  theilt";  and  further,  as  regards  the  difference  in  structure  of  the  sides 
of  this  species,  "Der  Schein  entsteht  durch  die  noch  dichtere  Zusam- 
mendrangung  der  Falten  der  wahren  und  falschen  Glieder  auf  der  concaven 
Seite. "  In  the  legend  (p.  61)  for  his  figure  6,  the  egg  of  C.  crassiceps,  he  also 
said  that  "  Jedes  Glied  hat  in  der  Mitte  eine  Falte,  die  ihm  das  Ansehen  giebt, 
als  bestunde  es  aus  zweiGUedem."  Thus,  there  is  reason  to  believe  that  for 
this  species  no  one  (apart  from  Linton's  Fig.  268)  has  as  yet  described  nor 
figured  what  the  writer  here  calls  spurious  articulations,  but  that  these  workers 
were  referring  to  the  secondary  division  of  the  segments  of  the  anterior  end 
of  the  strobila  which  proceeds  in  the  manner  described  for  B.  scorpii  et  al., 
altho  not  so  clearly  (Figs.  48  and  58).  This  is  borne  out  by  the  fact  that  the 
spurious  articulations  described  here  never  reach  the  m.edian  line  of  the  strobila, 
much  less  pass  completely  across  it  as  do  the  true  posterior  borders  of  the  pro- 
glottides (Fig.  74).  In  one  moderately  relaxed  strobila  the  first  segment  show- 
ing spurious  articulations  appeared  11.7mm.  from  the  tip  of  the  scolex,  while 
in  another  which  was  quite  contracted,  especially  anteriorly,  4.8nmi.  In  the 
former  case  the  next  two  pairs  of  these  structures — and  aU  of  these  in  question 
happened  to  be  bilaterally  symmetrically  situated — appeared  in  the  fourth 
and  thirteenth  segments  following. 

Posteriorly  the  uterus-sacs  appear  as  a  series  of  gradually  enlarging,  dark 
punctations,  as  described  below,  not  so  pronounced,  however,  as  in  B.  scorpii. 
The  measurements  of  the  first  proglottis  showing  eggs  in  the  uterus-sac 
in  a  fairly  relaxed  strobila  at  hand  were  0.50mm.  in  length  by  0.92  in 
breadth,  while  for  one  farther  back  where  the  uterus-sac  was  0.61  by  0.48 


160 


ILUNOIS  BIOLOGICAL  MONOGRAPHS 


[448 


mm.,  they  were  1.31mm.  in  length  by  0.82  in  width.  These  measurements 
are,  however,  of  only  relative  value.  Another  strobila  of  the  same  age  but  con- 
tracted at  the  time  of  fixation  might  show  the  same  regions  more  Uke  those 
farther  ahead  and,  thus,  in  alcohoUc  specimens,  evidently  younger. 

The  following  table  gives  various  external  measurements  of  six  specimens 
in  alcohol  for  the  purpose  of  comparison;  all  dimensions  are  in  milHmeters. 


Little 

T.ength  in  mm. 

87 

92 

43 

more  than 
scolex 

29 

72 

Length  of  scolez 

0.87 

0.59 

0.46 

0.43 

0.63 

0.83 

(lateral  view) 

Length  of  bothriimi 

1.08 

0.77 

0.64 

0.64 

1.00 

1.01 

Breadth  of  same 

0.75 

0.57 

0.52 

0.53 

0.67 

0.90 

Thickness  of  same 

0.87 

0.64 

0.68 

0.58 

0.74 

121 

Breadth  of  segment  I, 
anteriorly 

Much 

0.40 

0.37 

0.55 

0.92 

contracted 

Breadth  of  same, 

posteriorly 

Ditto 

0.53 

0.60 

0.53 

0.74 

1.16 

Thickness  of  same, 

posteriorly 

0.37 

0.38 

0.24 

0.27 

0.52 

„ 

Maximum  breadth  in 

anterior    part    of 

strobila 

1.01 

0.82 

1.06 

1.30 

Same  in  posterior  part 

of  strobila 

1.11 

1.04 

1.16 

1.48 

1.38 

The  cuticula  varies  in  thickness  from  2  to  5m,  the  most  common  measure- 
ment being  about  2.6jLt.  Resting  on  a  distinct  basement  membrane,  weU  shown 
after  the  use  of  MaUory's  stain,  it  is  divided  into  two  strata  of  equal  thickness 
by  a  granular  layer,  the  components  of  which  seem  to  be  related  to  the  bases  of 
the  stout,  somevs'hat  club-shaped  pseudocUia  or  "hairs"  which  constitute  the 
outer  moiety.  WTiile  the  inner  stratum  was  found  to  be  homogeneous  with 
the  stains  used,  the  outer  showed  two  intensities  of  color,  an  inner  Ughter  and 
an  outer  darker.  The  former  represents  the  narrowed  central  ends  of  the 
spindle-  or  club-shaped  pseudocilia,  while  the  latter  is  determined  by  the  well- 
stained  bodies  of  the  cirri  themselves.  Linton  (1901:473)  said  that  "the 
cutiaila  is  covered  with  minute  spines,"  but  Johnstone  (1909:89)  said,  con- 
cerning these  structures:  "I  can  see  nothing  of  this  kind  in  the  species  before 
me. "  All  over  the  scolex  and  in  the  form  of  a  band  on- the  posterior  borders  of 
the  proglottides  (Fig.  103)  these  cirri  become  modified  into  stouter  spinelets 
from  two  or  three  times  longer  than  elsewhere  and  everywhere  directed  pos- 
teriorly, quite  like  those  described  by  the  writer  (1914a  :85)  for  Eaplobotkrium 
globulijorme,  but  much  longer  relatively;  thus  indicating  their  function  as 
accessory  organs  of  attachment.  The  largest  spinelets  are  in  the  middle  of 
this  band,  those  at  the  edges,  that  is  in  the  anteroposterior  direction,  gradual- 


449]  PSEUDOPHYLLIDEA  FROM  FISHES— COOPER  161 

ly  merging  in  length  into  the  pseudocilia  of  the  cuticula  of  the  neighborhood. 
Furthermore  they  are  arranged  in  the  same  manner  on  the  posterior  borders 
of  the  spurious  articulations  and  of  aU  of  the  secondary  segments  situated  in 
the  anterior  portion  of  the  strobila.  They  were  referred  to  by  Wagener  (1854: 
5),  Diesing  (1863:236)  as  "articulo  singulo  .  .  .  postice  ciliis  instructo," 
Cohn  (1902:55)  and  by  Luhe  (1902:238,  247)  who  considered  "dass  es  sich 
nicht  um  in  die  Cuticula  eingesenkte  Stacheln  handelt,  wie  bei  dem  Stachel- 
kleide  so  vieler  Distomen,  sondem  nur  am  Fortsatze  der  Cuticula,  durchaus 
analog  denjenigen,  welche  Looss  an  der  bereits  oben  citierten  Stelle  fur  Haemo 
toloechm  asper  abgebildet  hat. " 

The  subcuticula,  about  20/Lt  in  thickness,  consists  of  fairly  elongated  cells, 
the  nuclei  of  which  are  situated  at  their  central  ends  close  to  the  vitelline 
follicles.  Their  boundaries  are  difficult  to  ascertain,  the  whole  layer  thus  being 
more  of  the  nature  of  a  syncitium.  For  about  one-third  of  their  length  im- 
mediately beneath  the  cuticula  the  cytoplasm  becomes  broken  up  into  a  num- 
ber of  more  or  less  parallel  processes  which  stand  out  in  distinct  contrast  with 
the  deeper  inner  ends  of  the  cells,  especially  in  transverse  sections. 

The  parenchyma,  everywhere  encroached  upon  by  the  voluminous  repro- 
ductive organs,  is  in  the  form  of  a  comparatively  open  reticulum  showing  no 
features  of  special  interest.  It  is  naturally  most  abundant  in  the  posterior 
flared  ends  of  the  proglottides.  In  small  strobilas  it  is  more  compact  in  struc- 
ture and  contains  relatively  more  nuclei.  Distinct  spaces,  formerly  occupied 
by  calcareous  bodies,  such  as  are  readily  and  distinctly  seen  in  the  parenchyma 
of  B.  SCOT  pit,  were  found  neither  in  the  scolex  nor  in  the  strobila;  nor  were  these 
structures  noticed  in  living  material. 

The  musculature  is  composed  of  the  typical  three  sets  of  fibres,  interfered 
with  in  the  usual  manner  by  the  large  reproductive  organs  and  their  external 
openings.  The  sagittal  and  frontal  series  are  only  moderately  developed,  while 
the  longitudinal  series  is  about  10,u  in  thickness  and  situated  within  the  frontal 
series.  Its  fibres  are  arranged  in  bundles  of  irregular  shape  (in  cross-section) 
and  width  but  of  this  uniform  thickness,  excepting  where  they  are  naturally 
much  flattened  out  dorsally  and  ventrally  by  the  distended  uterus-sac.  They 
are  also  continuous  from  joint  to  joint.  A  very  weakly  developed  series  of 
outer  longitudinal  muscles  is  present,  while  the  muscles  of  the  posterior  border 
of  the  proglottis  (vide  Liihe  1897a)  are  poorly  developed,  in  fact  even  less  so 
than  in  Bothriocephalus. 

In  the  scolex  the  frontal  fibres  are  better  developed  than  the  sagittal  ones, 
and  pass  around  the  bothrium  closer  to  its  lumen  than  to  its  external  surface, 
while  the  latter  are  mostly  confined  to  the  region  between  the  bothria.  The 
inner  longitudinal  muscles  of  the  strobila  pass  forward  into  the  scolex,  dividing 
as  they  meet  the  lumina  of  the  bothria  to  pass  around  them  and  attach  them- 
selves to  the  margins  of  the  apertures.  They  are  thus  directed  somewhat 
obhquely  as  shown  in  Johnstone's  figure  18  and  described  as  ".  .  .  nmning 
irregularly,  probably  obhquely,  round  the  walls  of  the  bothrium.  These  no 
doubt  function  as  constrictors  of  the  latter. "    A  few  pass  on  forward  to  the 


162  ILLINOIS  BIOLOGICAL  MONOGRAPHS  [450 

tip  of  the  scolex  to  assist  in  activating  that  region.  Between  the  bothria,  how- 
ever, they  were  found  to  be  separated  into  dorsal  and  ventral  layers  as  in  the 
strobila,  and  not  united  into  a  single  coronal  band,  as  shown  by  Johnstone. 
The  bothrial  sphincter  (Fig.  48)  is  a  powerful  bundle  of  fibres,  about  0.07mm. 
in  transverse  section  surrounding  the  aperture  close  to  its  cuticula.  In  trans- 
verse sections  of  the  scolex  it  appears  as  a  deeply  staining  mass  on  each  side 
of  the  opening,  also  shown  in  Johnstone's  figure  15.  As  it  crosses  the  aperture 
anteriorly  it  becomes  greatly  attenuated.  This  with  its  comparatively  great 
size  at  the  sides  and  posteriorly  accoimts  for  the  almost  complete  disappearance 
of  the  aperture  in  many  adult,  preserved  scolices  owing  to  the  powerful  con- 
traction of  this  muscle  from  behind  forward,  thus  diminishing  the  opening 
towards  the  tip  of  the  scolex.  From  their  arrangement  it  is  to  be  seen  that  this 
sphincter,  evidently  a  modified  group  of  frontal  fibres,  and  the  longitudinal 
muscles  in  the  scolex  play  a  more  important  role  in  the  movements  of  the 
bothria  than  do  the  other  groups.  On  account  of  their  obhque  course  the 
longitudinal  fibres  evidently  act  in  diminishing  the  size  of  the  lumen  of  the 
bothrium  as  well  as  do  the  circular  frontal  fibres  of  the  latter. 

The  nervous  system  consists  of  two  longitudinal  strands  which  enlarge  in 
tip  of  the  scolex  to  form  two  somewhat  elongated  gangUa.  The  latter  are  united 
by  only  a  few  fibres,  but  they  send  out  comparatively  large  nerves  to  the 
bothria.  In  the  strobila  the  chief  strands,  each  from  15  to  20/i  in  diameter,  are 
situated  ventrally  in  the  medullar}^  parenchyma,  just  within  the  longitudinal 
muscles  and  from  one-fifth  to  one-quarter  the  width  of  the  strobila  from  its 
lateral  margins  (Fig.  90).  About  halfway  along  the  scolex  the  strands  are 
about  80)u  in  diameter;  but  the  gangUa  are  somewhat  smaller  and  situated  close 
together  about  0.15mm.  from  the  summit.  In  other  words  the  chief  strands 
enlarge  and  diverge  gradually  until  the  equatorial  region  of  the  scolex  is  reached 
and  then  diminish  in  size  as  they  converge  to  form  the  ganglia.  A  pair  of 
prominent  nerves  is  sent  forward  on  each  side  to  supply  the  saddle-shaped 
groove  described  above.  In  young  strobilas  the  nerve  strands  are  situated 
midway  between  the  dorsal  and  ventral  surfaces,  and  not  ventrally. 

The  excretory  system  consists  of  a  pair  of  longitudinal  vessels,  situated 
ventrally,  that  is,  in  the  same  frontal  plane  as  the  chief  nerve  strands,  each 
vessel  being  in  the  anterior  end  of  the  strobila  about  halfway  between  the 
nerve  strand  and  the  median  row  of  reproductive  rudiments.  These  vessels 
break  up  in  a  very  irregular  manner  into  extremely  elongated  loops,  so  that  for 
considerable  stretches  four  vessels  will  appear  while  again  the  branchings  will 
be  so  mmierous  as  to  make  it  very  difficult  to  decide,  on  looking  at  a  transverse 
section,  which  are  the  main  channels  (Fig.  48).  In  other  individuals  four  ves- 
sels appear,  so  that  one  is  led  to  conclude  that  the  pair  just  mentioned  represent 
the  latter,  fused  at  times  but  separated  again  to  form  the  loops.  But  whether 
these  four  vessels  represent  the  typical  four  of  other  orders  is  a  matter  of  con- 
jecture. These  main  vessels  may  continue  back  into  the  ripe  joints  close 
alongside  the  uterus-sacs,  but  they  usually  break  up  into  a  very  diffuse  reticu- 
Ivmi  throughout  the  medullary  parenchyma  in  the  region  where  the  openings 


451]  PSEUDOPHYLLIDEA  FROM  FISHES— COOPER  163 

of  the  cirrus  and  vagina  pierce  the  cuticula  in  development.  Behind  this 
region  it  was  found  impossible  to  trace  the  main  vessels  with  satisfaction.  The 
system  usually  passes  into  the  scolex  as  two  vessels,  but  soon  breaks  up  into 
an  elaborate  net-work  which  ramifies  between  the  bothria  and  throughout 
their  walls.  These  branches  are  shown  in  Johnstone's  figure  15.  As  regards 
the  conditions  of  the  excretory  system  in  the  extreme  posterior  end  of  the 
strobila,  the  material  at  hand  permits  of  only  negative  conclusions.  In  the 
youngest  strobilas,  such  as  that  shown  in  figure  49,  the  vessels  converge  pos- 
teriorly to  open  into  a  notch  in  the  cuticula,  there  being  no  definite  terminal 
vesicle  such  as  is  present  in  plerocercoids  of  the  genus  Proteocephalus,  for 
instance.  From  this  and  the  further  fact  that  Wagener  (1857:93)  showed 
(Fig.  6,  PI.  II)  the  main  vessels  in  a  very  small  strobila,  which  he  examined 
while  it  was  alive,  passing  separately  to  the  outside,  one  is  led  to  conclude  that 
the  vesicle,  if  ever  present,  must  have  been  situated  in  the  walls  of  an  envelop- 
ing cyst  and  disappeared  with  the  latter  as  in  the  Trypanorhyncha  or  the 
Cyclophyllidea.  This  seems  to  have  been  Wagener's  idea  of  the  situation 
when  under  his  figure  65  (1854:68)  he  said:  "Man  sieht  keinen  pulsirenden 
Schlauch  am  spitzen  Schwanzende.  Es  muss  dies  Thier  auf  ahnliche  Weise 
entstanden  sein,  wie  das  in  Fig.  74  dargestellte, "  and  figure  74  is  that  of  "Di- 
bothrium  (Belones  ?)"  from  Scyllium  canicula  enclosed  in  a  cyst  in  the  walls 
of  which  "man  sieht  die  Gefasse  der  Cestodenblase. " 

The  earliest  reference  to  the  genitalia  of  C.  eras  sleeps  was  by  Rudolphi 
(1819:477)  who  said: 

"Ova  vel  ovaha  vel  ovata,  forsan  secundun  majorem  maturitatis  gradum. 
A  B.  punctato  diversissimus,  licet  ovaria  lateralia  fuscescant,  sed  haec  ipsa 
etiam  in  B.  crassicipite  quam  in  B.  punctato  majora  sunt." 

The  structures  called  ovaria  were  evidently  the  uterus-sacs.  F.  S.  Leuck" 
art  (1819:46)  described  the  reproductive  organs  of  his  B.  pilula  as  follows: 
" .  .  .  die  letzte  Half te  der  GHeder  breiter  als  lang,  mit  deutlichen,  weissen  ovar- 
ien.  An  den  unteren  Gliedem  sieht  man  oberhalb  jedes  Eierstockes  einen  was- 
serhellen  Punkt,  wahrscheinlich  Oeffnung  fur  das  mannliches  Zeugungsglied.' ' 
From  a  comparison  of  this  with  his  description  and  figure  of  posterior  proglot- 
tides of  B.  scorpii,  it  is  evident  that  he  too  was  dealing  with  the  uteri  and  their 
openings,  respectively.  He  also  referred  to  ".  .  .  den  schwarzen  Punkten 
des  Korpers,  die  Rudolphi  fur  Ovarien  gehalten"  of  Redi's  worm,  which  Rudol- 
phi called  (1810:67)  Bothriocephalus  gadi  merluccii  and  placed  in  his  "Species 
dubiae."  Wagener  (1854a :61)  said  that  "Die  Eier  haufen  sich  in  obersten 
Theile  der  Glieder  an.  Der  Dotterstock  verzweigt  sich  uber  das  ganze  Glied 
und  liegt  overhalb  der  vescicules  transparentes  van  Beneden.  Die  Gesch- 
lechtsoffnung  ist  in  der  Mitte  und  lateral."  Diesing  (1863:236)  placed  the 
"Aperturae  genitalium  laterales  in  Hnea  mediana."  Ariola  (1896:265-266) 
gave  the  first  comprehensive  description  of  the  reproductive  organs  in  the 
following  words: 

"Tuttaria  sul  corpo  si  osservano  macchie  scure  molto  sporgenti,  constituite 
della  massa  die  uova.    TaU  rilievi  non  sono  propriamente,  nella  linea  mediana, 


164  ILLINOIS  BIOLOGICAL  MONOGRAPHS  [452 

ma  collocati  a  destra  o  a  sinistra  die  essa  formando  in  tal  modo  une  striccia  a 
zig-zag. 

L'aperture  genitale  maschile  sbocca  sulla  faccia  dorsale,  e  sulle  opposta  si 
apre  I'utero.  In  alcune  proglottidi  I'ovario  e  bilobo,  la  uova  sono  ellissoidali  e 
mancano  di  operculo. " 

Liihe  (1899:42-44)  in  defining  the  characters  of  the  genus  gave  the  general 
features  of  the  genitaUa,  while  Ariola  (1900:397)  enlarged  his  own  1896  des- 
cription: "Ovario  con  numerose  uova,  talora  bilobo;  uova  eUissoidaU  aventi 
nel  diametro  longitudinale  61  n  e  nel  trasversale  32.  ..."  Braun  (1900) 
reviewed  the  literature  on  the  genus  and  species  up  to  date,  and  Volz  (1900) 
discussed  the  reproductive  organs  of  the  species  as  compared  with  those  of  his 
B.  spiraliceps  and  the  position  of  the  openings  in  connection  with  brief  remarks 
on  the  phylogeny  of  the  genus  Bothriocephalus  s.  lat.  As  regards  his  own  speci- 
mens Linton  (1901:473)  said  that  "Posterior  segments  show  rudiments  only 
of  the  reproductive  organs,  but  no  indication  of  external  genital  openings." 
And  later  Johnstone  (p.  89)  remarked  that  "the  genital  openings  are  in  the 
middle  Hne  of  the  proglottides  but  near  the  anterior  borders  of  the  latter," 
referring  evidently,  as  will  be  seen  later,  to  the  uterine  openings  only. 

The  rudiments  of  the  reproductive  organs  appear  about  three  millimetres 
from  the  tip  of  the  scolex  as  aggregations  of  nuclei  that  can  just  be  discerned 
in  toto  mounts  (Fig.  48).  About  three  millimetres  farther  posteriorly  in  mod- 
erately contracted  older  strobilas  (such  as  would  be  obtained  if  no  special  care 
were  taken  during  the  fixation  of  the  material)  the  cirrus  and  vagina  are  seen 
to  be  just  piercing  the  dorsal  surface.  Before  this  region  is  reached,  however, 
the  common  rudiment,  at  first  circular  and  then  elongated  oval  in  outline, 
differentiates  into  a  more  anterior  portion,  the  rudiment  of  the  whole  uterus, 
a  more  posterior  less  elongated  part,  the  beginnings  of  the  cirrus-pouch  and 
vagina,  and  a  third,  connecting  the  other  two  near  the  hinder  edge  of  the 
proglottis,  the  nuclear  aggregation  that  will  develop  into  the  ovaries  and  the 
organs  of  the  interovarial  space  (Fig.  74).  As  mentioned  in  the  specific  diag- 
nosis, the  first  two  of  these  rudiments  alternate  irregularly  from  side  to  side 
as  do  the  corresponding  adult  structures.  At  the  same  time  the  testes  and 
vitelline  glands  are  developing  in  the  medullary  and  cortical  portions  of  the 
parenchyma,  respectively. 

A  distinct  genital  sinus  or  cloaca,  the  opening  of  which  is  usually  almost 
circular  in  outUne,  is  present  (Fig.  75).  It  varies  from  0.05  to  0.09mm.  in 
diameter  and  is  situated,  as  above  noted,  nearly  in  the  median  line,  dorsally, 
and  from  three-fourths  to  one-half  the  length  of  the  proglottis  from  its  anterior 
border,  usually  just  posterior  to  the  spurious  articulations  when  they  are 
present.  At  the  bottom  of  this  sinus  there  is  a  secondary  cloaca  ("Gesch- 
lechstasche"  or  "Ductus  hermaphroditious"),  also  circular  in  outhne,  from  15 
to  25m  ill  diameter,  and  into  it  open  the  cirrus  and  vagina  quite  close  together, 
the  latter  immediately  behind  the  former.  This  secondary  sinus  is  best  seen 
in  sagittal  sections  (Fig.  103).  The  genital  pore  (the  opening  of  the  main 
sinus)  is  elevated  sUghtly  above  the  general  dorsal  surface  of  the  proglottis, 


453]  PSEUDOPHYLLIDEA  FROM  FISHES— COOPER  165 

thus  appearing  as  a  low  cone  or  crater.  No  sphincters  control  the  openings 
of  either  of  these  sinuses  but  the  cuticula  of  the  floor  of  the  larger  or  outer  is 
modified  to  form  coarse,  low,  rounded  and  closely  set  papillae  which  are  evi- 
dently of  special  importance  during  copulation.  These  papillae  would  evidently 
serve  to  temporarily  fasten  the  structure  into  the  primary  sinus  of  another 
proglottis,  when  it  is  possibly  everted  with  the  cirrus.  Copulation  v/as  not 
observed  in  this  species  during  life,  nor  were  any  cases  of  protruded  cirrus  met 
with  in  the  material  at  hand. 

All  of  the  proximal  portions  of  the  reproductive  organs,  excepting  the 
vitelline  foUicles,  are  located  in  the  medullary  parenchyma,  although  the  much 
distended  uterus-sac,  origmally  in  the  latter,  extends  almost  to  the  cuticula  on 
both  the  dorsal  and  ventral  surfaces.  Figure  75  shows  their  arrangement  in 
toto. 

The  testes  are  closely  arranged  in  the  medullary  parenchyma  in  two  lateral 
fields,  each  bounded  laterally  by  the  junctions  of  the  dorsal  and  ventral  layers 
of  longitudinal  muscles  and  medially  by  the  other  reproductive  organs  (except- 
ing the  vitelline  glands)  which  occupy  in  the  quadrate  proglottides  about  the 
middle  one-third  of  the  transverse  diameter  of  the  strobila  and  are  contiguous 
from  joint  to  joint.  In  the  quite  mature  elongated  proglottides  the  testes  are 
ellipsoidal  in  shape,  averaging  0.125mm.  in  length  by  0.040  in  diameter,  the 
cross-section  being  usually  about  circular  in  outline.  In  younger  joints  and  in 
all  those  of  much  contracted  strobilas  the  testes  are  nearly  spherical  in  shape, 
measuring  about  60/i  in  diameter,  or  often  slightly  longer  than  broad.  They 
are  arranged  in  a  single  layer  in  the  medulla,  the  whole  dorsoventral  diameter 
of  which  they  occupy,  and  are  continuous  from  proglottis  to  proglottis.  From 
2  to  4  appear  in  each  lateral  field  in  transverse  sections,  from  5  to  7  are  seen  in 
sagittal  sections  between  the  posterior  borders  of  consecutive  proglottides, 
while,  so  far  as  could  be  determined  from  frontal  series  directly,  the  number  is 
from  20  to  25.    Thus  each  proglottis  contains  from  40  to  50  testes. 

The  vas  deferens  forms  a  wedge-shaped  mass  of  closely  arranged  coils, 
extending  forward  immediately  ahead  of  the  cirrus-pouch  and  alongside  the 
uterus-sac  for  about  two-thirds  of  its  length  (Fig.  75) .  In  proglottides  in  which 
the  latter  is  yet  comparatively  small  the  vas  deferens  may  pass  forward  as 
far  as  its  anterior  end.  In  either  case  it  forms  witli  the  cirrus-pouch  a  mass 
which  alternates  from  right  to  left  with  the  uterus-sac.  When  distended  with 
sperms  the  duct  averages  about  SO/x  in  diameter;  but  just  before  it  enters  the 
cirrus-sac  anterodorsally  it  narrows  dovra  to  5ju.  Immediately  within  the  wall 
of  the  latter  it  often  enlarges  again  to  form  a  thin-walled  fimctional  vesicula 
seminalis,  or  perhaps  more  correctly  ductus  ejaculatorius,  from  13  to  23/*  in 
diameter.  After  one  or  two  short  turns  it  diminishes  again  to  about  8/li  and 
then  passes  on  as  the  cirrus  proper.  While  the  proximal  portions  of  the  duct 
do  not  pass  in  any  definite  direction,  the  latter  is  situated  for  most  of  its  length 
in  the  longitudinal  axis  of  the  pouch.  It  is  about  0.10mm.  in  length  and  about 
20  to  25/*  in  diameter  at  its  middle.  It  is  lined  with  a  cuticula,  lO/t  thick,  which 
is  cleft  but  not  armed  with  bristles  of  any  kind. 


166  ILUNOIS  BIOLOGICAL  MONOGRAPHS  [454 

The  cimis-sac  (Fig.  103),  situated  immediately  behind  the  uterus  sac  or 
lateral  to  its  posterior  end,  is  elliptical  to  slightly  oval  in  outline,  and  measures 
0.128  to  0.162mm.  long,  0.087  to  0.116  wide  and  0.098  to  0.116  deep.  The 
longitudinal  axis  is  directed  anterodorsally  from  the  genital  sinus  and  to  the 
right  or  left,  according  as  it  alternates  with  the  uterus-sac.  The  proximal 
one-third  of  the  contents  of  the  pouch  consists  of  loose  parenchymatous  tissue 
with  a  few  muscle  fibres  surrounding  the  ductus  ejaculatorius,  while  the  distal 
two-thirds,  that  part  which  accommodates  the  cirrus  proper,  is  supplied  mostly 
with  muscles  which  actuate  the  latter.  Large  fibres  proceed  somewhat  obli- 
quely from  the  wall  towards  the  proximal  pole  of  the  sac  to  become  broken 
up  or  frayed  before  they  are  attached  to  the  cirrus  tangentially,  so  as  to  give 
the  appearance  in  frontal  sections  of  the  latter  being  surrounded  by  a  com- 
paratively heavy  layer  of  fine  Hghtly  staining  circular  fibres.  A  few  of  the 
fibres  closest  to  the  cuticula  of  the  cirrus  were  considered  to  be  true  circular 
fibres;  but  no  longitudinal  fibres  were  seen.  The  wall  of  the  cirrus-sac  is  from 
2  to  3n  thick  and  is  made  up  of  very  fine  closely  matted  fibres,  the  direction 
of  which  could  not  be  determined  with  satisfaction.  The  sac  lies  freely  in  the 
parenchyma  of  the  region  and  is  not  connected  by  any  special  muscles  to  the 
dorsal  or  ventral  body-waUs;  nor  are  the  body  muscles  attached  to  it  as  in 
some  cestodes.  The  layers  of  the  latter  are  simply  pierced  and  the  fibres  turned 
aside  in  evidently  a  passive  manner. 

The  opening  of  the  vagina  is  close  behind  that  of  the  cirrus  at  the  bottom 
of  the  secondary  genital  sinus,  or  as  it  has  been  called  by  Fuhrmann,  "ductus 
hermaphroditic  us"  (Fig.  103).  From  this  point  the  duct  courses  ventropos- 
teriorly  in  the  mid-line  and  then  parallel  to  the  dorsal  surface  of  the  proglottis 
until  it  reaches  the  ovarian  isthmus,  above  which  it  makes  a  few  turns  and 
quickly  diminishes  from  20fi  in  diameter  half  way  along  its  course  to  lO/i.  It 
then  dips  farther  down  into  the  genital  space,  often  enlarging  shghtly  as  it 
does,  and  soon  joins  the  oviduct  at  an  enlargement  of  the  latter  situated  a 
short  distance  behind  the  oocapt.  Throughout  its  length  it  is  lined  with  a 
ragged  or  pseudocUiated  cuticula  and  surrounded  by  radially  arranged  nuclei 
connected  with  the  cuticula  by  cytoplasmic  strands  like  those  described  by 
the  writer  for  H.  glomdiforme  (1914a:105)  and  considered  to  be  possibly  ex- 
truded nuclei  of  the  original  epithehum  as  well  as  the  myoblastic  nuclei  of 
circular  fibres,  a  layer  of  which  surrounds  the  duct.  There  is  no  vaginal  sphinc- 
ter. 

In  his  generic  diagnosis  Luhe  states  that  the  receptaculum  seminis  is  small 
and  in  his  description  of  the  family  Ptychobothriidae  (1902:327)  says  that  when 
pres«it  it  is  "in  Gestalt  eines  kleinen  Blindsackchens  ausgebildet,  welches 
parallel  neben  dem  Endabschnitte  des  Oviduktes  liegt  and  mit  der  Vagina 
unmittelbar  vor  deren  Vereinigung  mit  dem  Ovidukt  in  Vergindung  steht." 
On  the  contrary  it  was  found  to  be  a  comparatively  large  structure  but  very 
difficult  to  orient  in  sections  made  in  any  direction.  It  is  in  the  form  of  a 
thin- walled  sac  about  60  by  20^,  wrapped  somewhat  spirally  around  the  dorsal 
wall  of  the  above-mentioned  enlargement  of  the  oviduct  and  opening  by  an 


455]  PSEUDOPHYLLIDEA  FROM  FISHES— COOPER  167 

aperture  equal  to  its  whole  diameter  into  the  vagina  just  at  its  juncture  with 
this  vestibule.  But  since  the  vagina  constantly  constricts  a  second  time  to  a 
diameter  of  about  8/x  before  entering  the  latter,  one  gets  the  impression  of  the 
receptaculum  seminis  being  a  diverticulum  of  the  oviduct  rather  than  of  the 
vagina.  Figure  108  of  four  consecutive  sections  of  a  transverse  series,  showing 
the  union  of  these  ducts,  v.'ill  give  a  better  idea,  perhaps,  of  the  nature  of  the 
seminal  receptacle. 

In  mature  proglottides  the  ovary  (Fig.  90)  is  a  bilobed  structure  situated  in 
the  median  hne,  close  to  the  posterior  border  of  the  proglottis  and  immediately 
ahead  of  the  uterus -sac  of  the  proglottis  following,  where  the  latter  is  much  dis- 
tended with  eggs  (Fig.  75).  In  toto  mounts  the  lobes  seem  to  be  quite  separate 
from  each  other,  but  in  sections  the  isthmus  is  easily  made  out.  It  occupies 
the  ventral  half  of  the  medulla  while  the  wings  or  lobes  extend  completely 
across  the  space  between  the  layers  of  longitudinal  body  muscles.  The  lobes 
are  about  0.27mm.  long  by  0.13  wide,  while  the  isthmus  is  0.06  to  0.08mm.  in 
anteroposterior  diameter.  These  proportions  are,  however,  much  dififerent 
in  much  contracted  strobilas  or  in  proglottides  in  which  the  uterus -sac  is  dis- 
tended with  eggs.  In  both  instances  the  ovary  is  very  much  flattened  antero- 
posteriorly  and,  in  the  latter  case,  all  but  obliterated,  as  shown  in  Liihe's 
figure  8  (1902:326).  The  ova  from  that  portion  of  the  isthmus  where  they 
are  ready  to  be  passed  on  by  the  oocapt,  are  elliptical  to  oval  in  outhne  in  sec- 
tions and  measure  on  the  average  18  by  10^,  their  nuclei  being  about  9/i  in 
diameter. 

The  oocapt,  situated  in  the  median  line  at  the  posterior  border  of  the  ovar- 
ian isthm.us,  somewhat  dorsally,  is  a  spherical  to  ovoid  muscular  organ  about 
20ju  in  diameter  (Fig.  103).  Immediately  behind  it  the  oviduct  constricts 
to  a  diamiCter  of  only  7  to  10/i  and  then  passes  on  posteriorly  and  ventrally  either 
to  the  right  or  to  the  left,  gradually  enlarging  until  the  above-mentioned  vesti- 
bule is  reached,  when  the  diameter  is  25  to  30ju.  The  latter  enlargement  is 
less  of  the  nature  of  a  direct  continuation  of  the  oviduct  than  a  more  or  less 
separate  thin-walled  structure — the  waUs  of  the  oviduct  up  to  this  point  being 
comparatively  thick  (Fig.  108) — into  which  the  oviduct  opens  by  a  sUghtly 
elongated  aperture.  While  the  w'all  of  the  first  portion  of  the  oviduct  consists 
of  more  or  less  cubical  ciliated  cells  with  som.ewhat  indefinite  boundaries — 
ordinarily  they  stain  very  densely — that  of  the  vestibule  shows  only  a  few 
scattered  nuclei  protruding  into  the  lumen.  The  oviduct  continues  postero- 
laterally  and  ventrally  from  one  corner  of  the  vestibule  (that  with  which  the 
vagina  is  usually  connected)  as  a  tube  quickly  diminishing  from  15  to  lOju  in 
diameter  and  lined  with  a  ciliated  epithelium  with  prominent  nuclei  but  no 
distinct  cell -boundaries.  Close  to  the  anterior  wall  of  the  uterus-sac  of  the 
succeeding  proglottis  it  turns  upward  sharply  and  at  about  the  middle  of  the 
dorsoventral  diameter  of  the  medulla  takes  on  the  vitelline  duct.  It  then  skirts 
the  uterus-sac,  just  mentioned,  as  it  passes  to  the  opposite  side  of  the  generative 
space  and  slightly  forward,  to  soon  become  surrounded  by  the  shell-gland. 


168  ILLINOIS  BIOLOGICAL  MONOGRAPHS  [456 

The  vitelline  duct  at  its  union  with  the  oviduct  has  a  diameter  of  8/:;  but 
just  beyond  this,  in  the  direction  of  the  follicles,  it  soon  enlarges  to  form  a 
somewhat  irregular  vitelline  reservoir  which  when  filled  with  yolk  may  attain 
a  diameter  of  30/x.  Its  general  course  is  towards  the  opposite  side  of  the 
generative  space  almost  parallel  to  either  surface  of  the  body;  but  beyond  this 
it  could  not  be  traced  with  satisfaction. 

The  vitelline  follicles  fill  up  ahnost  the  whole  of  the  cortical  parenchyma 
from  the  layer  of  longitudinal  body  muscles  to  the  nuclei  of  the  subcuticula, 
the  thickness  of  the  stratum  averaging  0.05mm.  (Fig.  90).  They  form  a  con- 
tinuous layer  around  the  margins  of  the  proglottides  (in  transverse  sections) 
and  also  from  proglottis  to  proglottis,  as  mentioned  above,  even  extending 
well  into  the  posterior  borders.  They  are  not  arranged  in  lateral  fields,  but 
are  interrupted  only  where  the  uterus  sac  and  genital  sinus  pierce  the  body- 
wall,  or  in  the  former  case  greatly  press  against  the  latter.  The  individual 
foUicles  attain  a  size  of  60/i  and  are  very  closely  crowded  together.  The 
number  in  cross-sections  of  the  proglottis  averages  55  and  in  sagittal  sections 
13,  thus  making  the  average  total  number  for  each  proglottis  715. 

The  shell-gland  is  situated  in  the  dorsal  portion  of  the  genital  space,  that 
part  of  the  oviduct  showing  the  connections  being  almost  horizontal  in  position 
and  about  18/*  in  diameter,  that  is,  a  Uttle  larger  than  the  oviduct  behind  that 
region.  The  individual  cells  of  the  gland  are  much  attenuated,  closely  ar- 
ranged and  have  their  nuclei  situated  in  their  sUghtly  enlarged  distal  ends. 
Their  connections  with  the  oviduct  give  the  wall  of  the  latter  a  honeycombed 
appearance  when  it  is  seen  in  longitudinal  section. 

Beyond  this  region  the  oviduct  gradually  enlarges  as  it  passes  above  the 
ovarian  isthmus  to  become  the  uterine  tube,  the  coils  of  which  are  accommo- 
dated opposite  the  cirrus  pouch  just  behind  the  uterus-sac.  As  it  proceeds 
its  wall  gets  thinner  and  the  nuclei  protrude  more  and  more  into  the  lumen 
imtn  many  of  them  are  evidently  lost.  It  is  noteworthy  that  the  uterine 
tube  in  many  cases  as  well  as  the  uterus -sac,  especially  in  younger  proglottides, 
alternates  irregularly  from  right  to  left  according  as  the  cirrus  and  vas  deferens 
do.  These  three  structures  are,  in  fact,  fitted  very  nicely  into  the  space  be- 
tween the  uterus-sac  ahead  and  the  ovarian  isthmus  behind. 

The  uterus-sac  is  elliptical  in  outline,  has  its  longitudinal  axis  directed 
anteroposteriorly,  and  is  situated  in  the  anterior  half  of  the  proglottis.  In 
very  mature  segments  it  occupies  almost  the  whole  of  the  medullary  region,  or 
to  be  more  precise,  the  middle  three-fifths  of  the  diameter  of  the  proglottis,  its 
anterior  end  extending  forward  close  to  the  ovary  of  the  proglottis  immediately 
ahead  (Fig.  75).  Liihe  (1902a:326)  figured  the  uterus  as,  to  use  his  own  words, 
"...  in  der  Regel  eine  geraumige  Uterushohle  bUdend,  welche  die  ubrigen 
Genitalorgane,  ohne  dass  freiUch  deren  Riickbildung  eintritt,  buchstablich 
an  die  Wand  drangen  kann.  indem  die  ganze  Proglottis  in  reifen  Proglottiden 
vielfach  als  ein  einziger  sackformiger  Eibehalter  mit  verbal  tnissmassig  sehr 
diinnen  Wandungen  erscheint. "  But  such  a  degree  of  restriction  of  the  other 
genitalia  was  seen  by  the  writer  only  in  a  few  of  the  ripe  proglottides  of  strobilas 


4571  PSEU DOPEY LLIDEA  FROM  FISHES— COOPER  169 

much  contracted  longitudinally.  There  the  largest  uterus-sac  measured 
0.8mm.  wide  by  0.67  long,  while  the  width  of  the  proglottis  in  question  was, 
at  the  posterior  borders  of  the  spurious  articulations,  1.57mm.  In  fairly  re- 
laxed strobUas  it  increases  in  dimensions  from  0.18  by  0.14mm.,  where  the  first 
eggs  appear  in  the  lumen,  to  0.87mm.  long  by  0.48mm.  wide,  where  the  proglot- 
tis is  0.80mm.  wide  at  its  middle,  in  the  latter  case,  of  course,  pressing  against 
the  dorsal  and  ventral  walls  even  as  far  as  the  cuticula.  From  a  comparison 
of  these  measurements,  and  the  fiirther  fact  that  in  the  case  of  the  former 
much  contracted  strobilas  there  often  appears,  behind  the  region  showing 
the  nearly  obHterated  genitaha,  a  more  relaxed  one  in  which  the  relations  of 
the  uterus-sac  to  the  other  organs  is  quite  as  in  the  competely  relaxed  strobilas, 
one  is  inclined  to  conclude  that  the  characters  of  the  family  above  quoted 
apply  to  this  species  only  in  the  case  of  proglottides  much  contracted  longitu- 
dinally. In  the  quadrate  proglottides  the  smaller,  that  is,  younger  sacs  alter- 
nate irregularly  from  right  to  left,  as  do  the  uterine  openings,  and  according 
as  the  cirrus  pouch  and  the  vas  deferens  in  particular  (on  account  of  its  above- 
mentioned  position)  occupy  the  opposite  sides  of  the  proglottis.  Externally, 
in  alcohohc  specimens,  the  uteri  appear  as  a  gradually  enlarging  series  of  brown 
punctations  caused  by  the  contained  eggs  showing  through  the  thinned  body 
wall,  as  pointed  out  originally  by  Rudolphi  and  other  viTiters. 

The  waU  of  the  uterus  consists  of  a  thin  membrane  on  the  inside  of  which 
a  very  few  scattered  and  somewhat  flattened  nuclei  indicate  its  original  epi- 
thelial nature.  In  young  proglottides,  where  no  eggs  are  to  be  seen  in  the 
small  uterine  cavities,  the  wall  is  composed  of  an  epitheHum  about  8iLc  thick, 
showing  prominent  nuclei  but  no  distinct  cell-boimdaries.  Furthermore 
in  such  early  stages  the  lumina  of  the  uterine  ducts,  developing  in  the  manner 
described  by  Young  (1913)  and  Shaefer  (1913),  are  not  completely  formed  nor 
in  connection  with  the  cavities  of  the  sacs,  but  the  uterine  apertures  are  promi- 
nent. In  the  first  two  or  three  sections  of  a  lOju  frontal  series,  taken  from 
the  ventral  surface,  they  appear  as  distinct  somewhat  eUiptical  apertures 
about  26/i  in  transverse  diameter,  but  in  the  third  or  fourth  section  are  closed, 
only  to  reopen  as  the  cavity  of  the  uterus-sac,  thus  showing  that  the  membrane 
closing  the  aperture  is  only  about  lOju  in  thickness.  And  this  closed  condition 
is  maintained  imtil  the  uterus-sac  attains  the  above-mentioned  maximum 
size  and  becomes  greatly  distended  with  eggs.  Then  the  functional  opening 
is  established  by  the  rupture  of  the  membrane  which  has  meanwhile  reached 
a  length  of  0.046  to  0.058mm.  by  a  width  of  0.034  to  0.046,  its  eUiptical  outhne 
thus  having  been  retained.  The  opening  does  not  become  as  regular  in  outline, 
however,  as  the  membrane,  for  the  latter  remains  around  the  rim  as  ragged 
processes,  which  render  the  determination  of  the  exact  location  of  the  aperture 
in  toto  mounts  a  matter  of  no  Uttle  difiiculty. .  The  uterus  opening  is  sur- 
rounded by  a  series  of  radiating  cells  like  those  of  the  opening  of  B.  scorpii 
described  above. 

The  fresh  eggs  examined  in  saline  solution  are  elliptical  to  ovoid  in  shape, 
75  by  40/x  in  dimensions  and  provided  with  a  thin,  very  light  brown  sheQ  hav- 


170  ILUNOIS  BIOLOGICAL  MONOGRAPHS  [458 

ing  no  operculum.  The  color  is  so  faint  that  it  can  be  seen  to  advantage  only 
when  the  eggs  are  in  masses  or  in  the  uterus-sac.  Ariola  (1900:397)  gave 
the  measurements  of  the  eggs  of  the  European  species  as  67  by  32iJ.  The  larg- 
est examined  were  immature,  the  contoits  consisting  of  large  spherical  cells 
only,  like  those  shown  by  Wagener  (1854a)  in  his  figure  6,  Taf.  I.  When  the 
worms  are  still  attached  to  the  wall  of  the  intestine  of  the  host  between  the 
mucous  folds,  they  often  discharge  many  of  their  eggs  from  most  of  the  posterior 
proglottides  when  their  scoUces  are  irritated  with  a  blunt  needle  in  order 
to  make  them  loosen  their  comparatively  firm  hold. 

Forty-four  specimens  of  Merluccius  hilinearis  were  examined  at  Woods 
Hole  and  at  Harpswell,  but  no  definite  idea  of  a  possible  intermediate  host  was 
obtained.  It  was  noticed,  however,  that  when  the  intestine  of  the  fish  con- 
tained much  grey  chyle,  presumably  the  result  of  the  digestion  of  small  her- 
ring— definitely  ascertained  at  South  Harps\\-ell  to  be  such  in  a  few  cases- 
and  of  Poniohbus  aestivalis  (Mitchill),  the  blueback — no  tape- worms  of  this 
species  were  present;  but  where  amphipoda  were  found  in  the  stomach  or  the 
remains  of  such  in  the  intestine  the  worm  was  plentiful.  Furthermore,  where 
nothing  was  found  in  either  stomach  or  intestines,  other  than  yellowish 
chyle  in  the  latter — as  in  most  fish  examined — indicating  amphipods  and 
other  small  crustaceans  as  food  rather  than  small  herring,  the  worm  was  also 
common.  All  stages  from  the  youngest  strobilas,  such  as  that  shown  in  figure 
49,  to  the  oldest  were  found,  but  none  nor  any  plerocexcoids  were  met  with  in 
the  course  of  the  thoro  dissection  of  the  available  stomach  contents  of  the 
hosts,  both  fish  and  crustaceans.  In  a  number  of  cases,  nevertheless,  only  very 
young  strobilas  were  foimd  in  the  intestine  of  the  host,  thus  pointing  to  p>ossible 
sudden  infections  at  different  times.  Wagener,  who  figured  the  youngest 
strobUa  that  has  yet  been  recorded,  in  fact  nothing  much  more  than  the  scolex, 
said  nothing  more  concerning  the  life  history  than  that,  on  accoimt  of  the  ex- 
cretory vessels  opening  separately  to  the  exterior  in  this  very  yoimg  specimen, 
there  might  possibly  have  been  a  vesicular  appendage  to  the  larva  in  the 
nature  of  an  enveloping  cyst  comparable  to  that  described  and  figure  for 
"Dibothrium  (Belones?)"  from  ScyUium  canicula,  concerning  which  he  said 
(Lc,  p.  45):  "Vergleicht  man  diese  Form  vom  Cysticercus  mit  den  vorigen 
[Cysticercus  fascicolaris  Rud.],  so  ergiebt  sich,  das  der  Unterschied  nur  in 
dem  Aufhangebeutel  sich  findet,  der  Kopf  und  Blase  verbindet. " 

A  detailed  description  of  the  species  is  here  given,  not  only  because  it  is 
evidently  the  only  one  belonging  to  the  genus,  but  because  descriptive  details 
are  so  lacking  from  the  European  Uterature  that  the  determination  of  the  spe- 
cies is  attended  with  considerable  imcertainty.  The  writer,  however,  considers 
that,  on  the  basis  of  the  pubHshed  accounts  and  reports  of  the  species,  but 
in  the  absence  of  European  material  for  comparison,  the  form  occurring  on 
this  side  of  the  Atlantic  Ocean  must  be  looked  upon  as  identical  with  the  C. 
crassiceps  of  Europe. 

The  material  studied  consisted  of  No.  204,  259,  261,  262,  269,  and  282  in 
the  writer's  collection  from  the  intestine  of  Merluccius  hilinearis  as  above  listed. 


4591  PSEU DOPEY LLIDEA  FROM  FISHES— COOPER  171 

AMPHICOTYLINAE  Liihe  1902 

Scolex  with  two  typical,  usually  not  very  deep  bothria,  which  in  some 
forms  develop  posterior,  sucker-like  portions.  In  an  isolated  case  a  pseudo- 
scolex  is  substituted  for  the  scolex.  External  segmentation  insignificant,  at 
times  disappearing  thru  accessory  wrinkling  or  folding  of  the  surfaces  of  the 
proglottides.  Opening  of  cirrus  and  vaginal  marginal,  irregularly  alternating, 
with  more  or  less  strongly  pronounced  tendency  to  unilaterality.  Uterus- 
opening  median;  uterus-sac  always  well  developed.  Coiling  of  vas  deferens 
strongly  expressed. 

Occurrence:  In  fishes. 

Type  genus:  Amphicotyle  (Diesing  1864)  Ariola  1900,  e.p.  Liihe  1902. 

ABOTHRIUM  van  Beneden  1871,  char,  emend.  Liihe  1899 


Taenia  (part.) 

Auctorum 

Rhytis  (part.) 

Zeder 

1803 

Bothriocephalus  (part.) 

Rudolph! 

1809 

Bothriocephalus  (part.) 

Rudolphi 

1819 

Bothriocephalus  (part.) 

Leuckart 

1819 

Dibothriiim  (part.) 

Diesing 

1850 

Bothriocephalus  (part.) 

Baird 

1853 

Dibothriiun  (part.) 

Diesing 

1863 

Bothriocephalus  (part.) 

Olsson 

1867 

Abothrium 

Beneden 

1871 

Abothrium 

Moniez 

1881 

Dibothrium  (part.) 

Linton 

1890 

Abothrium 

Lonnberg 

1891 

Bothriocephalus  (part.) 

Matz 

1892 

Bothriotaenia  (part.) 

Ariola 

1896 

Bothriotaenia  (part.) 

Riggenbach 

1896 

Abothrium 

Liihe 

1899 

Bothriotaenia  (part.) 

Ariola 

1900 

Abothrium 

Liihe 

1900 

Abothrium 

Liihe 

1910 

Scolex  not  exceptionally  elongated,  with  two  powerful  but  not  especially 
deep  bothria.  Segmentation  in  older  portions  of  the  strobila  usually  insigni- 
ficant on  account  of  superficial  wrinkling  of  the  individual  proglottides;  ripe 
proglottides  essentially  broader  than  long.  Longitudinal  nerves  near  the 
lateral  borders,  dorsal  to  the  cirrus-sac  and  vagina.  Testes  exclusively  be- 
tween the  nerve  strands.  Vitelline  foUicles  of  very  irregular  shape,  in  two 
broad  lateral  fields,  in  part  at  least  between  the  bundles  of  the  longitudinal 
muscles,  the  follicles  of  individual  proglottides  not  especially  separated  from 
one  another.  Ovary  scarcely  lobed,  more  or  less  bean-  or  kidney-shaped. 
Shell-gland  dorsal  to  the  ovary.  Uterus-sac  in  ripe  proglottides  occupying 
the  whole  of  the  medullary  parenchyma.  The  openings  of  the  uteri  correspond 
to  a  more  or  less  prominent  median  longitudinal  furrow  of  the  chain  of  proglot- 
tides. 

Type  species:  A.  rugosum  (Batsch), 


172 


ILLINOIS  BIOLOGICAL  MONOGRAPHS 


[460 


ABOTHRIUM  RUGOSUM  (Batsch  1786) 
[Figs.  32-36,  63,  76,  91,  109] 

1773  Taenia  decimpoUicaris 

1781  Taenia  tetragonoceps  (part.) 

1782  "  Der  runzlichter  Fischbandwunn  " 
1786  Taenia  rugosa 
1788  Taenia  tetragonoceps  (part.) 
1790  Taenia  rugosa 

1802  Taenia  rugosa 

1803  Rhytis  conoceps 
1810  Boihriocephalus  rugosus 
1816  Bothrioceophalus  rugosus 
1819  Bothriocephalus  rugosus 
1819  Bothriocephalus  rugosus 
1845  Bothriocephalus  rugosus 
1850  Dibothrium  rugosum 
1853  Bothriocephalus  rugosus 
1863  Dibothrium  rugosum 
1867  Bothriocephalus  rugosus 
1871  Abothrium  gadi 
1881  Abothrium  gadi 
1889  Bothriocephalus  rugosus 

1889  Bothriocephalus  rugosus 

1890  Dibothrium  rugosum 

1890  Abothrium  rugosum 

1891  Abothrium  rugosum 

1892  Bothriocephalus  rugosus 
1894  Bothriotaenia  rugosa 
1896  Bothriotaenia  rugosa 
1896  Bothriotaenia  rugosa 

1898  Bothriotaenia  rugosa 

1899  Abothrium  rugosum 

1900  Boihriotaenia  rugosa 

1900  Abothrium  rugosum 

1901  Dibothrium  rugosum 
1903  Bothriotaenia  rugosa 
1910  Abothrium  rugosum 

Specific  diagnosis:  With  the  characters  of  the  genus.  Large  cestodes 
with  maximum  length,  breadth  and  thickness  of  1(X)0,  7  and  2mm.,  respectively. 
Scolex  present  only  in  very  young  strobilas,  when  conical  and  provided  with 
very  weak  bothria,  changing  with  age  to  a  pseudoscolex  of  various  shapes, 
usually  imbedded  in  pyloric  cecum  of  host.  Proglottides  at  first  broad  and 
very  short,  obscured  by  irregular  transverse  and  longitudinal  rugae,  then 
gradually  lengthening  with  age  until  finally  quadrate  or  longer  than  broad. 

Cuticula  5/i  thick,  subcuticula  0.14mm.  Small  calcareous  bodies,  20/i  in 
length.  Longitudinal  muscles  in  bimdles,  transverse  forming  septa  between 
proglottides.  Nerve  strands  45^*  in  diameter.  Two  chief  excretory  vessels 
anteriorly,  passing  into  30  to  35  posteriorly. 

Genital  cloaca  irregularly  alternating,  between  first  and  second  thirds  of 
edges  of  proglottides.  Vagina  opens  immediately  behind  the  cirrus  and 
slightly  ventral;  no  hermaphroditic  duct. 


Strussenfelt 

1773 

:27 

Pallas 

1781 

:88 

Goeze 

1782 

:410 

Batsch 

1786 

:208 

Schrank 

1788 

:46 

Gmelin 

1790 

:3078 

Rudolphi 

1802 

:107 

Zeder 

1803 

:292 

Rudolphi 

1810 

:42 

Lamarck 

1816 

:168 

Rudolphi 

1819 

:137 

Leuckart 

1819 

:57 

Dujardin 

1845 

:618 

Diesing 

1850 

:591 

Baird 

1853 

:88 

Diesing 

1863 

:239 

Olsson 

1867 

:53 

Van  Beneden 

1871 

:56 

Moniez 

1881 

:167 

Linstow 

1889 

:242 

Monticelli 

1889 

:68 

Linton 

1890 

:750 

Lonnberg 

1890 

:22 

Lonnberg 

1891  ; 

:75 

Matz 

1892  ; 

:113 

Blanchard 

1894  ; 

:701 

Ariola 

1896  ; 

:280 

Riggenbach 

1896: 

223, 228 

Muehling 

1898  : 

;35 

Liihe 

1899  : 

39 

Ariola 

1900  ; 

:432 

Liihe 

1900a 

:101 

Linton 

1901: 

412,476 

Schneider 

1903  : 

:7 

Ltihe 

1910  : 

26 

461] 


PSEUDOPHYLLIDEA  FROM  PISHES— COOPER 


173 


Testes  discontinuous  from  proglottis  to  proglottis,  ellipsoidal,  flattened 
anteroposteriorly,  40  by  90  by  85m,  and  45  to  60  in  number.  Vas  deferens 
lateral  to  uterus-sac  with  few  coils  before  entering  the  cirrus-sac,  350  by  70  to 
80/i.  Cirrus-sac  ovoid  \A'ith  narrow  end  outward,  174  to  277^1  long  by  92  to 
102/1  in  diameter.  Cirrus  straight  in  outer  half  of  sac,  proximally  coiled  or 
dilated. 

Ovary  large,  entire,  kidney-shaped  (isthmus  as  thick  as  the  wings),  0.6nmi. 
wide,  occupying  the  posterior  half  of  the  median  portion  of  early  mature  seg- 
ments. Ova  conspicuous,  nuclei  large,  10  to  13/*  in  diameter.  Oocapt  34fM 
in  diameter.  Beginning  of  oviduct  S-shaped.  Right  and  left  vitelline  ducts 
join  ventrally;  common  duct  acts  as  reservoir.  Vitelline  follicles  entirely 
within  longitudinal  muscles,  discontinuous,  intermingling  laterally  with  the 
testes,  irregular  in  shape  and  size,  largest  30,  90  and  70/x  in  length,  -width  and 
thickness,  respectively.  Shell-gland  compact.  Uterine  duct  with  only  a  few 
coils  close  to  the  median  line;  uterus-sac  very  wide  and  short,  or  irregularly 
circular  or  quadrate  surficiaUy,  often  lobed,  0.75  to  1.6mm.  in  transverse  dia- 
meter, constantly  rounded  laterally;  openings  in  median  zig-zag  row. 

Eggs,  80  to  98/i  long  by  75  to  92/i  wide,  shell  quite  transparent. 

Habitat:  Intestine  of  the  host  with  pseudoscolex  imbedded  in  a  pyloric 
coecum. 


HOST 

LOCAUTY 

COLLECTOR 

AUTHORITY 

Gadus  mustela 

Borke 
Wagler 

Goeze 
Goeze 

1782  :  410 

Gadus  mustela 

1782  :  411 

Gadus  aeglifinus 

Warberg 

Olsson 

Olsson 

1867  :  54 

Gadus  aeglifinus 

Bergen 

Lonnberg 

Lonnberg 

1890  :  22 

Gadus  aeglifinus 

Grafvema  and 

Naset 

Olsson 

Olsson 

1893  :  17 

Gadus  aeglifinus 

Arctic  Ocean 

Zool.  Mus.  d. 
K.  Akad.  Wiss., 
Petrograd 

Linstow 

1901  :  281 

Gadus  aeglifinus 

England 

NicoU 

Nicoll 

1907  :  71 

Gadus  callarias 

Woods  Hole, 
Mass. 

V.  N.  Edwards 

Linton 

1898  :  431 

Gadus  callarias 

Arctic  Ocean 

Zool.  Mus.  d. 
K.  Akad.  Wiss., 
Petrograd 

Linstow 

1901  :  281 

Gadus  callarias 

Murman-Kiiste 

Zool.  Mus.  d. 
K.  Akad.  Wiss., 
Petrograd 

Linstow 

1903  :  19 

Gadus  callarias 

Nokujev  Id., 
Arctic 

2^1.  Mus.  d. 
K.  Akad.  Wiss., 
Petrograd  (Baer) 

Linstow 

1903  :19 

Gadus  lota 

Greiphswald 

Rudolphi 

Rudolphi 

1810  :  43 

Gadus  merluccius 

Rennes,  France 

Dujardin 

Dujardin 

1845  :  617 

Gadus  ntorrhua 

Warberg 

Olsson 

Olsson 

1867  :  54 

Gadus  ntorrhua 

Grand  Banks, 
Newfoundland 

Lee 

Linton 

1890  :  750 

174 


ILLINOIS  BIOLOGICAL  MONOGRAPHS 


[462 


HOST 

LOCALITY 

COLLECTOR 

AUTHORITY 

Gadus  morrhua 

Bergen 

Lonmberg 

Lonnberg       1890  :  23 

Gadus  pollachius 

Rennes 

Dujardin 

Dujardin       1845  :  617 

Gadus  pollachius 

Warberg 

Olsson 

Olsson            1867  :  54 

Gadus  pollachius 

Bergen 

Lonnberg 

Lonnberg       1890  :  22 

Gadus  pollachius 

Grafvema  & 
Naset,  Sweden 

Olsson 

Olsson            1893  :  17 

Gadus  pollachius 

Millport,  Scotland 

NicoU 

NicoU             1910  :  355 

Lota  vulgaris 
Lota  vulgaris 

Siebold 

Baird             1853  :  89 

Memel  and 

Muehling 

Muehling       1898  :  35 

Rossitten 

Lota  vulgaris 

Tvarminne  Id., 
Finland 

Schneider 

Schneider       1903b  :  8 

Morrhua  aeglifinus 

England 

Cobbold 

Cobbold        1858  :  158 

Morrhua  vulgaris 

England 

Cobbold 

Cobbold         1858  :  159 

Morrhua  vulgaris 

Belgian  coast 

van  Beneden 

van  Beneden  1871  :  56 

Merlangus  carhonarius 

England 

Cobbold 

Cobbold        1858  :  159 

Merluccius  vulgaris 

Warberg 

Olsson 

Olsson            1867  :  54 

Mdanogrammus  aeglifinus 

Woods  Hole 
Region 

Sumner,         1913  :  586 
Osbom 

and  Cole 

Microgadus  tomocod 

Woods  Hole 
Region 

Sumner,         1913  :  586 
Osbom 

and  Cole 

Urophycis  tenuis 

Wr>f>d<!  TTnlp 

, 

Sumner,         1913  :  586 
Osborn 

11  VMAAo  Xi.wiC 

Region 

and  Cole 

Melanogramtnus  aeglifinus 

Passamaquoddy 

Cooper 

Cooper 

Bay,  New  Bruns. 

(the  present  paper) 

Mdanogrammus  aeglifinus 

Bay  of  Fundy, 

Cooper 

Cooper 

Campobello  Id. 

(the  present  paper) 

Mdanogrammus  aeglifinus 

Freeport,  N.  S. 

Cooper 

Cooper 

(the  present  paper) 

Gadus  callarias 

Campobello  Id. 

Cooper 

Cooper 

(the  present  paper) 

Gadus  callarias 

Woods  Hole 

V.  N.  Edwards 

Cooper 

Region 

(the  present  paper) 

This  species  was  first  described  by  Goeze  (1782:410)  under  the  name  of 
"Der  runzlichter  Fischbandwoirm "  and  not  as  Taenia  rugosa,  as  indicated 
by  many  later  WTiters,  including  such  authorities  as  Liihe,  Braun  and  Ariola. 
It  was  Batsch  (1786:208)  who  gave  the  specific  name  on  the  basis  of  Goeze's 
description.  The  latter,  in  fact,  in  a  foot-note  (p.  410)  accepted  Pallas' 
T.  tetragonoceps  to  be  synonymous  with  the  forms  he  studied,  at  least  in  part, 
since  he  recognized  that  they  were  at  the  same  time  unlike  those  figured  by  Pallas 
after  Bloch,  from  the  "  Madui-morane  "  and  the  "  Rheinlachs. "  It  remained 
for  Rudolphi  (1810:42)  to  give  a  somewhat  more  detailed  description,  which 
seems  to  have  been  accepted  by  Diesing  (1850,  1863)  and  others,  altho  Dujar- 


4631  PSEUDOPHYLLIDEA  FROM  PISHES— COOPER  175 

din  (1845:617)  and  Cobbold  (1858:158)  made  important  additions  to  the 
knowledge  of  the  species.  Van  Beneden  (1871:56)  erected  the  new  genus, 
which  was  later  accepted  by  Lonnberg  (1891:75)  who  used  his  specific  name 
gadi  as  synonymous  with  the  B.  rugosus  of  the  earlier  writers.  Fraipont 
(1880:267;  1881:12)  added  to  the  knowledge  of  the  excretory  system.  It  was 
not  until  some  time  later,  however,  that  Linstow  (1889:242)  essayed  to  give 
a  more  detailed  description  of  the  whole  worm,  while  Lonnberg  (1891:75) 
and  Matz  (1892:113)  by  their  attention  to  the  anatomy,  especially  of  the  re- 
productive organs,  laid  the  foundation  upon  which  all  the  writers  since  have 
based  their  conceptions  of  the  species.  While  the  development,  especially 
in  its  earUest  stages,  was  studied  by  Schaviinsland  (1885:527),  and  later  by 
Saint-Remy  (1900:296),  the  systematic  position  has  since  then  been  dealt 
with  by  Blanchard  (1894:701),  Ariola  (1896:272,  274;  1900:432),  Riggenbach 
(1896:223)  andLiihe  (1899:33;  1900a:47,  96, 101;  1910: 26).  Linton  (1890:750; 
1898:431)  is  the  only  writer  who  has  described  the  species  in  America. 

The  dimensions  of  the  species  are,  according  to  Liihe  (1910:26),  400mm. 
to  1  meter  in  length  by  2  to  5mm.  in  maximvmi  breadth;  while  Ariola  (1900: 
433)  gave  the  total  length  of  the  strobila  as  from  16  to  97cm.  Linton  (1890: 
751)  worked  with  specimens  from  the  cod,  the  largest  of  which  measured 
655mm.  in  length  by  maximimi  breadth  and  thickness  (posteriorly)  of  6  and 
2mm.,  respectively.  The  largest  studied  by  the  writer  was  a  fairly  contracted 
one  (No.  301,  below)  from.  Gadus  callarias,  416mm.  in  length  by  7mm.  in  maxi- 
mum breadth  100mm.  from  the  incomplete  posterior  end  and  5mm.  at  the 
posterior  end. 

As  the  names  used  by  Goeze,  Batsch  and  Rudolphi  indicate,  this  species 
is  characterized  by  its  transverse  wrinkles  or  folds,  often  irregular  and  compli- 
cated by  longitudinal  grooves  and  folds  anteriorly  but  regular  and  correspond- 
ing to  the  internal  segmentation  posteriorly,  and  by  the  general  tumid  appear- 
ance of  the  strobila  due  to  the  very  large  uterus-sacs  gorged  with  eggs.  But 
most  striking  of  all  is  the  presence  of  a  pseudoscolex  which  is  found  embedded 
in  the  intestinal  coeca  or  intestinal  wall  of  the  host,  from  which  it  is  extracted 
only  by  careful  dissection.  Goeze  (1782:412,  Figs.  1,  4  and  5)  described  a 
scolex,  somewhat  elongated,  sagittate  and  irregular  but  otherwise  comparable 
to  that  of  other  bothriocephaUds,  while  Rudolphi  (1810:43)  does  not  seem  to 
have  foimd  anything  of  such  a  structure  in  Gadus  lota.  Dujardin  (1845:  617) 
was  evidently  the  first  to  describe  the  pseudoscolex  by  saying  that,  "  ...  la 
partie  anterieure  [of  the  strobila]  engagee  dans  I'appendice  pylorique  forme 
une  sort  de  bouchon,  un  cylindre  irregulier,  cartilagineux,  long  de  18mm., 
large  de  4mm.,  ride  ou  toruleux  et  sans  ancune  trace  d'organisation  ..." 
This  description,  however,  was  not  recognized  by  Diesing  (1850:590),  but  he 
accepted  Rudolphi's  diagnosis,  namely,  "Caput  subsagittatum,  bothriis 
oblongis  lateralibus.  ..."  Baird  (1853:89)  evidently  saw  two  bothria, 
probably  owing  to  the  fact  that  he  was  dealing  with  specimens  from  Lota 
vtdgaris  (vide  infra).  Cobbold  (1858:158,  159)  was  well  acquainted  with  the 
pseudoscolex,  since  regarding  individuals  from  the  cod  Q'Morrhua  vtdgaris") 


176  ILLINOIS  BIOLOGICAL  MONOGRAPHS  [464 

he  said  "In  a  cod  examined  on  the  15th  of  March,  1885,   two    specimens 
of  Bothriocephalus  rogosus  had  severally  attained  a  length  of  nearly  fifteen 
inches,  and  their  anterior  segments  for  an  inch  or  more  downwards,  were  so 
firmly  impacted  within  the  pancreatic  coeca,  that  it  was  found  impossible 
to  dislodge  them  without  injuring  the  filamentary  head  and  neck.    As  if 
to  make  the  anchorage  doubly  sure,  the  cartilaginous  thickening  of  the  invaded 
pancreatic  coecum  had  degenerated  into  a  calcareous  and  contracted  cylinder, 
twisted  upon  itseK  in  various  ways."    Olsson  (1867:54)  likewise  found  a 
pseudoscolex  in  this  species,  which  he  described  as  being  degenerated  m  Gadus 
morrhua  to  a  yellow,  elongated  mass  which  disintegrated  on  contact  with 
water.    It  was  18  to  25mm.  in  length  by  about  one-half  a  millimetre  in  diame- 
ter, while  its  position  was,  as  usual,  in  the  wall  of  a  pyloric  appendage  of  the 
host.    He  also  figured  a  young  strobila  from  Gadus  aegUfinus,  the  scolex  of 
which  he  considered  to  have  been  invaginated.    In  his  new  genus  and  species, 
Abothrium  gadi,  van  Beneden  (1871:56)  observed  the  pseudoscolex  stating 
that  "lis  ont  la  t^te  vers  le  fond  des  coecums  pyloriques,  percent  ordinaire- 
ment  les  parois  et  forment,  par  la  gaine,  souvent  dure  et  entortUlee  comme  une 
tabulaire,  une  saiUie  a  la  surface  de  cet  organe. "    So  far  as  the  writer  is  aware, 
he  gave  the  first  figure  of  the  structure,  as  it  is  commonly  met  with,  encased, 
however,  by  the  walls  of  the  pyloric  coecimi  in  which  it  was  found  lodged. 
Von  Linstow  (1889:242)  described  and  figured  a  scolex  somewhat  similar  to 
that  of  A.  crassum,  excepting  that  the  apex  was  hollowed  out  to  form  a  six- 
comered  opening  which  communicated  with  both  bothria.    Linton  (1890: 
750)  found  pseudoscolices  in  examples  from  the  codfish,  "Gadus  morrhua," 
which  were  much  as  described  by  Olsson,  since  he  said  that  "each  of  the 
specimens  in  this  lot  has  the  head  and  anterior  part  of  the  body  buried  in  the 
pyloric  caeca,  where  they  have  imdergone  degeneration  to  such  an  extent  that 
no  appearance  of  bothria  remains.    Around  the  parts  thus  enveloped  by  the 
caeca  is  a  yellowish  waxy  deposit,  the  degenerated  tissue  of  the  caeca.    This 
adventitious  tissue  invested  the  worm  so  closely  that  it  would  be  absolutely 
impossible  for  the  parasite  to  free  itself  from  its  host. "    The  next  important 
reference  to  the  scolex  was  by  Lonnberg  (1891:75)  who,  while  accepting  van 
Beneden's  new  genus,  Abothrium,  referred  the  species  back  to  rugosum  of 
Batsch,  and  described  the  metamorphosis  of  the  anterior  end  of  the  strobiJa 
into  the  well-known  pseudoscolex,  accounting  for  the  various  forms,  such  as 
figured  here.    It  is  noteworthy,  however,  that  he  did  not  state  specifically 
that  bothria  are  present  in  very  young  scohces,  before  this  transformation 
takes  place,  nor  did  he  give  any  figures  to  illustrate  the  latter.    Matz  (1892: 
114)  described  and  figured  a  typical  scolex  for  a  specimen  36cm.  long  from  Lota 
vulgaris,  while  Schneider  (1903a:9)  in  delineating  a  similar  structure  for  the 
species  from  the  same  host,  pointed  out  its  great  similarity  to  the  scolex  of 
B.  proboscideus  (=A.  crassum).    Perhaps  of  significance  in  connection  with 
the  question  of  the  metamorphosis  of  the  organ  is  his  statement  that  "Der 
ganze  Scolex  kann  sich  namlich  durch  verschiedene  Contraction  seiner  Mus- 
kebi  in  ein  pfeilformiges,  oder  fast  cubisches,  oder  sogar  sichelformiges  Gebilde 


465]  PSEU DOPEY LLIDEA  FROM  FISHES— COOPER  177 

verwandeln. "  Later  Johnstone  (1907:170)  described  the  pseudoscolex  with 
considerable  detail,  finding  quite  the  same  conditions  as  did  Linton.  On  ac- 
count of  never  meeting  with  anything  like  a  typical  scolex  in  adult  worms  he 
was  led  to  conclude  that  "Probably  in  young  codling,  recently  infected,  a 
stage  of  the  cestode  with  such  a  scolex  might  be  found  but  doubtless  with  in- 
creasing age  the  changes  mentioned  above  occur,  and  the  normal  structure 
of  the  head  disappears."  And  lastly,  Scott  (1909:85)  made  somewhat  similar 
statements,  pointing  out  that  "  ...  no  satisfactory  description  of  this  part 
of  the  v/orm  [the  pseudoscolex]  has  yet  been  pubhshed."  Thus  it  is  seen 
that,  apart  from  Olsson's  (1867:54)  finding  in  Gadus  aeglifinus  of  a  possible 
young  stage  in  the  degeneration  of  the  scolex  of  this  species,  no  one  has,  as 
yet,  figured  in  detail  its  metamorphosis,  Lonnberg,  however,  giving  the  only 
description  of  the  process.  On  the  other  hand,  a  typical  scolex  has  been  des- 
cribed by  several  writers,  as  pointed  out  above,  for  what  has  been  taken  to  be 
the  same  species  in  Lota  vulgaris^  but  since  there  is  evidence  that  the  latter  is 
quite  different  from  the  species  found  in  marine  Gadidae  and  since  the  speci- 
mens from  Lota  maculosa,  studied  by  the  writer,  were  found  to  belong  to  the 
well  known  A.  crassum,  a  pseudoscolex  must  be  attributed  only  to  adults  of 
A .  rttgosum,  at  least  until  the  confusion  which  exists  in  the  literature  regarding 
the  form  from  Lota  can  be  cleared  up  by  further  investigation. 

Two  forms  of  pseudoscolex  which  were  dissected  out  by  the  writer  from  the 
pyloric  ceca  of  Melanogrammus  aeglifinus,  the  haddock,  and  Gadus  callarias, 
the  cod,  are  shown  in  figures  35,  36,  respectively,  the  latter  being  from  the 
largest  specimen  at  hand;  while  what  is  doubtless  a  younger  stage  in  the 
degeneration  of  the  scolex  is  shown  in  figmre  34  from  the  intestine  of  a  had- 
dock. A  series  of  transverse  sections  of  the  latter,  brought  out  that  the  inter- 
nal anatomy  was  quite  suggestive  of  a  typical  scolex,  that  of  A.  crassum,  for 
example.  As  shown  in  the  figure,  the  structure  is  somewhat  flattened  in  the 
dorsoventral  direction.  While  there  were  only  faint  suggestions  of  bothria, 
especially  towards  the  tip,  the  arrangements  of  the  muscles,  nerves  and  ex- 
cretory vessels  pointed  to  its  being  possibly  not  far  removed  from  the  typical 
form  of  scolex.  This  view  is  supported  by  the  fact  that  it  was  found  free  in 
the  anterior  part  of  the  intestine  of  the  haddock,  altho,  unfortunately,  the 
length  of  the  strobila  was  not  recorded.  Among  a  lot  of  material  taken  from 
several  haddock  two  examples  of  the  true  scolex,  as  it  would  seem  to  be  at  or 
about  the  time  degeneration  sets  in,  were  found.  The  first  one,  shown  in  figure 
32,  was  from  the  smallest  strobila  at  hand,  22mm.  in  length,  while  the  other, 
figure  2)3,  was  from  an  older  chain,  only  the  anterior  end  of  which  was  present 
with  a  length  of  32mm.  and  maximum  breadth  of  2.5.  The  second  is  evidently 
the  older  from  the  standpoint  of  metamorphosis,  since  it  is  more  conical 
and  less  separated  from  the  neck  region  which  is  slightly  swollen;  while  the 
bothria  are  disappearing  as  the  whole  structure  is  approaching  the  stage  repre- 
sented by  figure  34.  In  figure  32  are  seen  somewhat  more  efficient  bothria, 
but  the  shape  of  the  organ  points  to  a  considerable  amount  of  degeneration 
having  already  taken  place.    The  next  stage  in  the  degeneration  of  the  scolex 


178  ILLINOIS  BIOLOGICAL  MONOGRAPHS  [466 

is  represented  by  figure  35.  Here  the  structure  is  likev^ise  not  embedded  in 
the  wall  of  the  pyloric  cecum  in  which  it  is  found  but  free  in  its  lumen,  the 
anchorage  for  the  strobila  being  obtained  by  the  close  approximation  of  the 
mouth  of  the  cecimi  aroimd  the  narrow  neck  region  and  the  concomitant 
swelling  of  the  more  distal  portions.  Furthermore,  the  indications  are  that  a 
considerable  portion  of  the  anterior  end  of  the  strobila  is  involved  in  the 
formation  of  the  organ,  especially  since  it  is  comparatively  large.  The  final 
stage  is  that  shown  in  figure  36,  where  degeneration  has  gone  on  to  such  an 
extent  that  there  remains  only  a  filamentous,  homy  or  cartilaginous  yellow 
mass,  deeply  and  firmly  embedded  in  the  wall  of  the  cecum.  Only  the  tip 
is  shown,  there  having  been  about  6mm.  more  to  the  region  where  it  left  the 
host  tissues  and  passed  insensibly  on  to  the  anterior  portion  proper  of  the 
strobDa.  The  latter  showed  only  faint  transverse  wrinkles  and  no  distinct 
division  into  segments,  as  is  seen,  with  some  irregularity,  however,  in  figure  32. 
This  form  of  pseudoscolex  was  foxmd,  as  described  by  Olsson,  Linton  and 
Johnstone,  to  be  surroimded  by  the  tissue  of  the  cecum  degenerated  to  a 
yellow  waxy  mass  which,  when  freed  from  the  surrounding  tough  tissue, 
crumbled  easily  under  the  dissecting  instruments. 

The  strobila,  at  first  almost  cylindrical  in  shape,  gradually  becomes  wider 
and  more  depressed  imtil  the  maximvim  breadth  near  the  posterior  end  is  at- 
tained. As  regards  the  form  of  the  segments  Dujardin  said  that,  ".  .  .  le 
reste  du  corps  long  de  100  a  140mm.,  large  de  2mm.  en  avant  et  de  6.5  en 
arriere,  est  Ubre  dans  I'intestin  et  forme  d'articles  tres  courts,  inegaux  ou 
dilates  ca  et  la;  .  .  .";  and  Linton  stated  that,  "The  body  is  not  dis- 
tinctly segmented  at  first,  but  is  crossed  by  innumerable  fine  wrinkles. "  While 
the  latter  statement  is  in  the  main  true,  and  appUes  particularly  to  the  yoimgest 
strobilas,  many  species  show  that  these  rugae,  altho  much  obscured  by  irregular 
longitudinal  grooves,  are  simply  due  to  the  formation  of  extremely  short  seg- 
ments which  correspond  proportionately  vAth.  the  much  more  distinct  ones 
farther  back.  These  segments  gradually  elongate  as  they  pass  backward 
until  the  end  proglottides  are  often  quadrate  or  even  longer  than  broad,  depend- 
ing on  the  degree  of  contraction  or  relaxation.  Linton  gave  the  length  of  the 
segments  near  the  middle  of  the  strobila  as  from  0.7  to  1.0mm.  and  posteriorly 
0.45,  and  the  thickness  as  2mm.  The  latter  was  2.5mm.  in  the  largest  speci- 
men examined  by  the  writer.  The  openings  of  the  uteri  on  the  ventral  surface 
of  the  strobila  form  collectively  a  sort  of  shallow  groove,  more  pronoimced,  of 
course,  posteriorly  but  quite  obliterated  when  the  segments  are  considerably 
relaxed. 

The  anatomy  of  the  species  was  first  given  careful  attention  by  Linstow 
(1889:235).  Later  Lonnberg  (1891:75)  and  Matz  (1892:113)  published  more 
accurate  descriptions  to  which  most  of  the  writers  since  have  referred.  That 
of  Lonnberg  was  foxmd,  however,  to  be  most  applicable  to  the  material  at  hand 
from  the  cod  and  the  pollack,  for  Matz  was  dealing  with  specimens  from 
Lota  vulgaris  and  Linstow  apparently  confused  the  two  possible  species  from 
Lota  and  the  marine  Gadidae  {inde  infra). 


467]  PSEU DOPEY LLIDEA  FROM  FISHES— COOPER  179 

Linstow  included  in  his  conception  of  the  cuticula  not  only  the  cuticula 
proper,  which  he  stated  was  Z.Zn  in  thickness,  but  also  the  outer  clear  zone  of 
the  subcuticula  which  he  found  to  be  49/x  thick.  In  the  present  study  the 
cuticula  was  found  to  be  about  5m  thick  and  to  be  divided  into  the  three  zones 
described  by  Lonnberg;  viz.,  an  outer  pseudociliated  or  ragged  layer,  occupying 
almost  one-half  of  the  thickness  of  the  whole  membrane,  a  middle  homogeneous 
principal  stratum,  and  an  innermost  basement  membrane  which  stands  out 
quite  distinctly  in  this  species  without  the  use  of  any  special  stains.  The  sub- 
cuticula was  found  to  average  0.14mm.  in  thickness,  the  clear  outer  ends  of 
the  elongated  cylindrical  and  closely  crowded  cells  being  cqjlectively  22>n  thick. 
The  whole  cortex  in  transverse  sections  has  a  depth  of  0.32mm.  Small  cal- 
careous bodies,  quite  difficult  to  distinguish  from  parenchymatous  nuclei,  are 
present  as  described  and  figured  by  Lonnberg.  They  are  oval  to  elliptical 
in  outline  and  have  a  maximimi  length  of  20iu. 

The  musculature  is  well  developed,  and  is  peculiar  in  that  the  sagittal  fibres 
especially  retain  their  myoblasts,  which  are  very  easily  recognized  in  sections. 
*'They  extend  from  the  dorsal  to  the  ventral  surface  and  are  usually  attached 
to  the  cuticula  with  their  ends,  but  often  fasten  on  to  the  walls  of  the  excretory 
vessels  or  other  organs.  Their  number  rises  considerably  with  increasing  age 
of  the  proglottis.  Since  they  pass  thru  the  spaces  between  the  bundles  of 
longitudinal  muscles,  they  are  partially  arranged  in  fasicles.  These  muscles 
have  not  only  a  nucleus,  but  often  also  surrounding  the  same  a  quite  large, 
spindle-shaped  protoplasmic  mass;  and  one  easily  finds  the  different  develop- 
mental stages  from  a  spindle-shaped  ceU  to  fully  developed  muscle  fibres  of 
typical  appearance,  where  the  protoplasm  is  already  transformed  and  reduced, 
and  only  the  nucleus  persists. "  They  are  only  slightly  more  numerous  between 
the  sets  of  reproductive  organs  than  elsewhere.  In  this  region,  on  the  other 
hand,  the  transverse  series  form,  as  emphasized  by  Lonnberg,  a  distinct  parti- 
tion separating  all  constituents  of  the  genitaha  of  successive  proglottides,the 
testes  and  vitelline  foUicles  especially  (cf.  A.  eras  sum).  In  transverse  sec- 
tions they  form  a  "plate,"  bounding  the  medulla  externally  on  each  siu'face, 
from  which  a  few  fibres  pass  farther  out  among  the  bvmdles  of  longitudinal  mus- 
cles. The  latter  are  arranged  in  two  distinct  layers,  each  about  0.15mm.  in 
thickness  in  the  median  Hne,  which  gradually  diminish  towards  the  edges  of 
the  strobila  where  they  join  thru  several  sm-aU  and  very  irregular  bundles. 
These  larger  fasicles  are  further  subdivided  dorsoventrally  into  smaller  ones 
of  various  sizes,  all  of  which  are  connected  longitudinally,  however,  by  strands 
passing  from  one  to  the  other,  as  pointed  out  by  Lonnberg.  In  the  anterior 
end  of  the  strobila,  as  one  foUows  them  forwards,  the  fasicles  of  longitudinal 
fibres  become  less  and  less  distinct,  but  extend  to  the  tip  of  the  scolex,  or  young 
pseudoscolex,  as  the  case  may  be,  scattering  considerably  as  they  go.  In 
sections  thru  the  structure  showTi  in  figure  ZZ,  a  small  number  of  sagittal  and* 
transverse  fibres  and  a  very  few  radial  ones,  situated  between  the  grooves  seen 
externally  proves  that  it  is  a  scolex,  but  a  poorly  developed  one,  or,  as  indicated 
above,  one  sho\ving  early  stages  in  the  process  of  degeneration  to  form  the 


180  ILLINOIS  BIOLOGICAL  MONOGRAPHS  [468 

pseudoscolex.  This  latter  statement  applies  in  a  greater  degree  to  the  struc- 
ture shown  in  figure  34,  since  in  it  still  more  degeneration  is  present  to  the 
extent  that  no  traces  of  the  radial  fibres  are  to  be  seen  altho  there  are  very  shal- 
low bothrial  depressions.  In  each  case  there  appears  in  the  medulla  and  among 
the  longitudinal  muscles  near  the  tip  of  the  organ  a  considerable  amount  of  a 
material  which  takes  the  Orange-G  co-unterstain  very  readily.  WTiile  this  is 
relatively  more  abundant  in  the  older  of  the  two  pseudoscoHces  in  question 
jind  intermingled  mth  a  good  deal  of  calcareous  material,  it  is  confined  more 
1.0  the  very  tip  of  the  yoimger  organ.  It  represents  possibly  tlie  first  stages  in 
the  development  of  the  yeUow  homy  material  seen  in  the  oldest  and  most  degen- 
erate pseudoscolices. 

Each  of  the  chief  nerve  strands  has  a  diameter  of  about  45)u  and  is  situated 
usually  dorsal  to  the  cirrus  and  vagina,  but  occasionally  ventral.  Linstow 
(1889:243)  gave  the  diameter  as  56/i.  Near  the  scolex  of  the  youngest  strobila 
at  hand  it  was  found  to  be  only  about  34/x  and  traversed  with  transverse  and 
sagittal  muscle  fibres.  Within  the  scolex  the  two  strands  gradually  converge 
and  become  united  between  the  bothria  by  several  v.eak  and  indistinct  strands 
in  lieu  of  a  commissure. 

The  excretory  vessels  are  small  and  irregular  in  number  and  arrangement 
in  the  mature  segments.  Lonnberg  gave  their  number  as  10  in  young  segments 
and  from  30  to  35  in  mature  proglottides,  but  anteriorly  and  in  young  strobilas, 
there  are  two  chief  canals,  as  stated  by  Linstow,  close  within  the  nerve 
strands,  accompanied  by  several  smaller  ones.  They  break  up  in  the  pseudo- 
scolex into  an  irregular  plexus  and  posteriorly  in  the  youngest  strobilas  empty 
into  the  terminal  vesicle,  shown  in  figure  63. 

The  first  traces  of  the  rudiments  of  the  reproductive  organs  were  seen  5.2mm. 
from  the  anterior  end  of  the  smallest  strobila  found,  which  was  22mm,  in 
length.  The  genital  cloacae  alternate  irregularly  from  side  to  side,  altho  they 
may  be  situated  on  one  side  for  stretches  involving  at  least  five  proglottides. 
Dujardin  (1845:617)  described  them  as  being  unilateral  or  very  irregularly 
alternating,  while  Linstow  (1889:244)  said  they  were  one-sided,  and  between 
the  middle  and  hinder  one-third  of  the  edges  of  the  proglottides.  In  the  sec- 
tions made  they  were  found  between  the  first  and  second  thirds,  often  covered 
by  the  edge  of  the  proglottis  next  ahead  and  from  35  to  75/i  in  depth.  Since 
the  actual  opening  is  usually  closed  by  the  longitudinal  contraction  of  the 
strobila,  it  is  difficult  to  distinguish  it  externally  from  grooves  separating  con- 
secutive proglottides  or  other  lateral  grooves  between  irregular  rugae.  The 
vagina  opens  immediately  behind  the  cirrus  and  slightly  ventral,  there  being 
no  distinct  ductus  hermaphroditicus.  This  corresponds  with  Lonnberg's  and 
Linton's  finds,  whereas  Linstow  said  that  it  is  opened  ahead  of  the  cirrus. 

The  testes  are  arranged  in  two  lateral  fields  between  the  nerve  strands  and 
the  uterus  and  ovary  in  the  median  line,  and  are  strictly  discontinuous,  that  is, 
separated  longitudinally  into  sets  corresponding  with  the  other  genitalia  by  the 
transverse  muscular  septa  between  proglottides.  Their  average  maximum 
length,  width  and  depth  are,  respectively,  40,  90  and  85iu,  thus  indicating 


469]  PSEULOPHYLLIDEA  FROM  FISHES— COOPER  181 

that  they  are  usually  quite  flattened  anteroposteriorly.  Linstow  gave  the 
diameter  as  0.06mm.  As  stated  by  Lonnberg,  they  show  various  stages  in  the 
development  of  spermatozoa  quite  well.  Altho  Linstow  described  them  as 
being  arranged  in  an  elongated  half-ring  on  each  side,  they  were  found  by  the 
writer  to  occupy  all  parts  of  the  medulla  in  the  fields  indicated,  interminghng 
irregularly  with  the  vitelhne  foUicles,  but  in  general  more  numerous  in  the 
median  frontal  plane.  From  23  to  30  are  present  in  each  lateral  field,  thus 
making  the  total  number  for  the  proglottis  from  about  45  to  60.  The  vas 
deferens  forms  an  elongated  mass  of  coils  in  the  anterior  portion  of  the  proglot- 
tis, which  extends  from  the  uterus-sac  to  the  cirrus-sac,  near  which  its  coils  are 
fewer  in  number  and  more  openly  arranged.  The  whole  mass  has  a  length 
(transversely)  of  •0.35mm.  by  a  diameter  (longitudinally)  of  0.07  to  0.08.  As 
pointed  out  by  Liihe  (1900a)  the  duct  forms  within  the  cirrus-sac  a  proximal 
winding  ductus  ejaculatorius — it  is  often  quite  dilated — and  a  distal  straight 
cirrus  proper,  which  occupies  half  the  length  of  the  sac.  The  cirrus-sac  varies 
in  length  from  174  to  277iJ,  and  in  maximum  diameter,  medially,  since  the  whole 
is  ovoid  with  the  narrow  end  outward,  from  92  to  102/x.  Liihe  gave  the  mea- 
surements as  220  by  75  to  90;:.  As  noted  by  the  same  vmter,  myoblastic  nuclei 
form  such  a  thick  layer  outside  of  the  wall  and  there  are  so  many  parenchy- 
matous nuclei  within  the  sac,  that  the  wall  itself  is  at  first  difficult  to  locate  in 
sections.    The  cirrus  proper  may  have  a  dorsoventral  diameter  of  40/:. 

The  vagina  has  a  diameter  of  20ju  as  it  passes  the  cirrus-sac,  and  is  lined 
with  a  comparatively  thick  cuticula.    Liihe  stated  that  the  ventral  bow  in  its 
course  is  more  median  than  in  A.  crassum,  but  in  the  material  sectioned  the 
very  reverse  was  found  to  be  the  case.    The  ovary  of  this  species  is  very  con- 
spicuous  since  it  is  large  (0.6mm.)  wide  compact  and   somewhat  kidney- 
shaped;  Linstow's  measurements  are  0.14mm.  wide  by  0.12  long.    There  is 
no  distinct  isthmus,  or,  as  Lonnberg  stated,  there  is  a  very  broad  one,  both 
longitudinally  and  dorsoventrally,  from  the  middle  of  the  anterior  face  of 
which  the  oviduct  arises  either  towards  the  dorsal  or  the  ventral  surface.    The 
ova  are  large  and  conspicuous  because  of  their  prominent  nuclei  which  are 
from  10  to  13/i  in  diameter,  while  their  nucleoh  are  about  2.5/x.    Linton  (1890: 
752)  gave  these  data  as  8  to  14  and  2.5/:,  respectively.    The  oocapt  has  a  dia- 
meter of  about  34/t.     From  it  the  oviduct  proceeds  laterally  at  first,  then  with 
a  sharp  turn  back,  i.e.,  "towards  the  side  opposite  the  genital-opening,"  it  is 
joined  by  the  vagina  just  before  it  makes  a  second  turn  towards  the  dorsal 
surface  of  the  proglottis  (Fig.  109).    The  viteline  follicles  are,  as  stated  by 
Lonnberg,    entirely    within    the    parenchymatous    muscle-sac — and    thus 
discontinuous  longitudinally — altho  Liihe    (1910:26),   probably   basing  his 
statements  on  Matz's  (1892:113)  description,  said  that  they  are  "...  zum 
Teil  noch  nach  inner  von  der  Langsmuskulatur. "    They  are  arranged  in  two 
lateral  fields  corresponding  to  those  occupied  by  the  testes  with  which  they 
intermingle  freely,  altho  being  situated  more  peripherally.    They  are  somewhat 
irregular  in  shape  and  size,  but  usually  compressed  anterposteriorly,  and  as 
much  as  90/:  wide,  30  long  and  70  thick.    There  is  a  m.edian  field  free  of  them 


182  ILLINOIS  BIOLOGICAL  MONOGRAPHS  [470 

both  dorsally  and  ventrally.  Right  and  left  vitelline  ducts  passing  to  the 
median  line  close  to  the  ventral  layer  of  transverse  muscles  unite  ventrally 
to  form  a  common  duct,  which  acts  as  a  yolk  reservoir.  The  imion  of  the 
common  vitelline  (Fig.  109)  duct  with  the  oviduct  takes  place  in  the  median 
frontal  plane,  a  Httle  aside  from  the  median  line  and  just  beyond  the  bend  in 
the  oviduct  before  which  is  located  the  point  of  union  of  the  vagina.  The 
shell-gland  is  quite  compact  and  situated  close  to  the  dorsal  wall  of  the  medulla. 
The  uterine  duct  takes  only  a  very  few  short  coils,  mostly  in  the  dorsoventral 
direction  close  to  the  median  line,  before  passing  into  the  very  capacious  uterus- 
sac.  The  latter  vies  with  the  large  ovary  in  filling  up  the  median  portion  of 
the  medulla,  and  measures  in  mature  (not  gravid)  proglottides,  0.74mm.  wide, 
0.74  long  and  0.37  deep,  being  ob\dously  quite  flattened  in  the  antero-posterior 
direction  as  are  the  other  organs.  In  mature  proglottides  which  are  quadrate 
in  shape  it  may  be  still  somewhat  elliptical  in  outline,  as  much  as  1.6mm.  long  by 
1.3mm.  wide,  and  show  distinct  lobations;  whereas  the  widest  and  most  gravid 
joints  may  be  Httle  else  than  sacs  of  eggs,  the  rest  of  the  reproductive  system 
in  both  cases  having  almost  entirely  degenerated.  The  uterus-sacs  were  con- 
stantly found  to  be  rounded  or  lobate  laterally,  as  stated  by  Matz  and  Liihe. 
The  openings  form  a  somewhat  irregular  zig-zag  row  on  the  ventral  surface 
of  the  strobila,  without,  however,  being  accommodated  in  a  distinct  groove. 

The  eggs,  taken  from  gravid  uteri  and  measured  in  the  formalin  in  which 
the  strobilas  were  preserved,  were,  externally,  80  to  98)u  long  by  75  to  92  wide; 
mantle,  67  by  62/:;  "ectoderm "  (of  Schauinsland), 62  by  54/i; and  oncosphere,  52 
by  40ju.  The  similar  data  given  by  Dujardin,  which  were  considered  by  Lin- 
stow  to  be  not  of  this  species,  were:  shell,  80  to  110  by  50  to  57^4;  "ectoderm," 
or  inner  shell,  51  to  57/i;  oncosphere,  48  to  50/i.  Linstow's  figures,  copied  by 
Liihe,  were  59  by  43a£. 

The  earUest  stages  in  the  development  of  this  species  have  long  been  known 
from  the  work  of  Schauninsland  (1885:527),  who  followed  it  to  the  escape  of 
the  oncosphere  enclosed  in  the  non-ciliated  mantle.  Saint  Remy  (1900:296-7) 
thought  that  he  probably  saw  polar  bodies  and  the  male  and  female  pronuclei 
among  other  important  finds,  and  came  to  the  conclusion  "...  que  les 
phenomenes  sont  essentiellement  les  mdmes  chez  les  Bothriocephales  et  chez 
les  Taenia  et  se  resument  dans  la  constitution  de  deux  enveloppes  autour  de 
I'embryon  hexacanthe."  Olsson  found  a  small  strobila  22mm.  in  length  in 
Gadus  aeglifinus,  which  he  considered  to  belong  to  this  species;  but  apart  from 
this  there  seem  to  be  no  other  references  in  the  literature  to  the  development 
of  the  strobila  from  the  plerocercoid.  As  stated  above,  the  smallest  found  by 
the  writer  was  also  22mm.  in  length,  but  no  such  invagination  of  the  scolex  as 
mentioned  by  Olsson  was  observed. 

As  stated  above,  there  is  considerable  evidence  in  the  literature  of  this 
species  to  indicate  that  the  form  found  in  marine  Gadidae  and  called  A .  gadi 
by  van  Beneden  (1871:56)  is  not  the  same  as  that  found  in  the  only  fresh- 
water gadid,  viz.,  Lota.  In  endeavoring  to  place  a  number  of  specimens  from 
Lota  maculosa,  it  was  found  that  in  many  points  they  agreed  with  the  descrip- 


471]  PSEUDOPHYLLIDEA  FROM  FISHES— COOPER  183 

tion  given  by  Matz  for  A.  rugosum.  The  scolices  are  more  or  less  alike, 
no  pseudoscolex  (see  below,  however)  being  present;  the  longitudinal  muscles 
are  not  in  bundles;  the  genital  cloacae  are  irregularly  alternating  from  side  to 
side;  the  vagina  opens  ahead  of  the  cirrus  instead  of  behind;  the  testes  are 
continuous  from  proglottis  to  proglottis;  the  vitelline  follicles  are  located  among 
the  longitudinal  muscles  and  are  discontinuous;  and  the  uterus-sacs  are  rounded 
laterally.  In  most  of  these  and  in  many  more  points,  on  the  other  hand,  the 
form  agrees  with  A.  crassum,  so  that  the  writer  is  obliged  to  consider  it  to 
belong  to  that  species.  Furthermore,  a  direct  comparison  of  Matz's  description 
with  that  of  Lonnberg  brings  out  many  differences.  Lonnberg  described  a 
pseudoscolex,  calcareous  bodies,  the  longitudinal  muscles  in  bundles,  the 
other  sets  of  parenchymatous  muscles  as  above  described,  the  vagina  opening 
behind  the  cirrus  and  ventrally,  testes  discontinuous,  vitelHne  follicles  within 
the  parenchymatous  muscle-sac  and  also  discontinuous,  none  of  which  char- 
acters are  to  be  found  in  Matz's  description,  but  all  of  which  apply  to  the 
material  at  hand  from  marine  Gadidae.  It  is  to  be  noted  here  that  Lonnberg 
accepted  the  specific  name  rugosum  of  Rudolphi  instead  of  the  gadi  of  van  Bene- 
den,  which  as  will  be  seen  presently  may  not  be  admissable.  Going  back, 
then,  to  the  only  other  and  the  earliest  description  of  the  anatomy  of  the  spe- 
cies, namely,  that  of  Linstow  (1889:242-5),  similar  difficulties  and  confusion 
are  met  with.  Linstow  gave  as  hosts  for  the  species,  which  he  called  B.  rugosus 
Rud.,  Gadus  aeglifinus,  G.  morrua,  Merlangus  carbonarius,  M.  poUachius,  Mer- 
lucius  vulgaris^  Lota  vulgaris,  L.  molva  and  Motella  mustda.  Characters  in 
his  description  not  applicable  to  the  material  studied  are:  No  pseudoscolex, 
but  scolex  of  a  rather  peculiar  shape  and  structure  terminally;  nerve  strand 
56^1  in  diameter;  10  excretory  vessels  anteriorly  arranged  in  two  groups  of 
five  each;  genital  cloacae  unilateral,  between  the  middle  and  hinder  thirds 
of  the  edge  of  the  proglottis;  vagina  opening  ahead  of  the  cirrus;  length  of 
cirrus-sac  0.42mm.  (!) ;  ovary  0.14  by  0.12mm.. ;  uterus  spherical  when  obviously 
young;  and  eggs  59  to  43//.  Testes  with  a  diameter  of  60/i,  vagina  16  to  26//  in 
diameter  at  the  beginning,  and  two  vitelline  ducts,  besides  a  few  other  minor 
points  in  the  general  anatomy,  agree,  however,  with  the  species  as  studied  by 
the  writer.  Thus  it  is  seen  there  is  by  no  means  anything  like  complete  agree- 
ment as  regards  details  among  the  three  descriptions  by  Linstow,  Lonnberg 
and  Matz.  But  this  does  not  seem  to  have  inconvenienced  many  of  the  writers 
since  then,  notably  Ariola  (1900:432)  and  even  Liihe  (1900a)  whose  references 
to  the  position  of  the  vitelline  follicles  and  the  ventral  bow  in  the  vagina  are 
at  variance  with  conditions  described  here;  altho  Johnstone  (1907),  Scott  (1909) 
and  Nicoll  (1910)  were  obviously  deahng  with  the  form  described  by  Lonnberg, 
Schneider  (1903a  :7-10)  seems  to  have  been  the  only  one  who  pointed  out  the 
differences  between  the  form  from  Lota  and  that  from  marine  Gadidae.  He 
said:  ^' Botkriotaenia  rugosa  gleicht  sowohl  in  ihrem  Aussehen,  als  auch  in 
ihrer  Anheftungsweise  ausserordentlich  der  Species  B.  prohoscidea,  die  in 
unseren  Lachsen  (Salmo  salar)  so  massenhaft  vorkommt.  Trotzdem  pflegt 
man  aber  seit  Rudolphi,  soviel  mir  bekannt,  immer  die  in  Lota  meist  vorkom- 


184  ILLINOIS  BIOLOGICAL  MONOGRAPHS  [472 

mende  Form  als  eine  getrennte  Species  auf  zufassen  unter  dem  Namem  '  rugo- 
sa'  (Bothriocephalus  rugosus  Rud.  =  Dibotkrium  rugosum  Diesing,  u.s.w.),  ob- 
gleich  die  unterscheidenden  Merkmale  zwischen  B.  proboscidea  und  B.  rugosa, 
die  Riggenbach  in  seinen  'Bemerkungen  ueber  das  Genus  Bothriotaenia  Railliet' 
iibersichtlich  zusammenstellt,  recht  unbedeutend  sind  und  vielleicht  doch 
noch  in  Rahmen  der  Variationsbreite  einer  einzigen  Species  untergebracht  wer- 
den  konnen;"  and,  as  regards  the  latter,  in  a  footnote:  "Die  von  M.  Liihe 
...  als  Unterscheidungsmerkmal  vorgeschlagene  Lage  der  Dotterstocke 
zum  Theil  (B.  rugosa),  bzw.  auschliesslich  (B.  proboscidea)  zwischen  den  Langs- 
muskeln,  scheint  mir  auch  nicht  genugend  constant  sein,  um  als  Speciesmerk- 
mal  verwandt  werden  zu  konnen. "  For  material  from  Lota  vtUgaris  Schneider 
described  a  scolex  and  segments  both  similar,  as  he  pointed  out,  to  those  of 
B.  proboscidea  (  =  A.  crassum).  The  arrangement  of  the  genital  cloacae, 
irregularly  alternating  but  unilateral  for  long  stretches,  the  openings  of  the 
uteri  in  a  longitudinal  furrow,  the  early  form  of  the  uterus-sac  and  the  size  of 
the  eggs  (64.5  by  50  to  52/i),  as  described  by  the  same  worker,  all  agree  with 
A.  crassum  as  studied  by  the  writer.  In  conclusion  Schneider  said:  "Uebri- 
gens  habe  ich,  wie  gesagt,  auch  an  die  Examplaren  aus  dem  Museum  keine 
Pseudoscolexbildung  bemerkt  und  zweifle  daran,  dass  B.  rugosa  und  B.  gadi 
ein  und  dieselbe  Art  sind, "  and  further,  "Es  ist  mir  iibrigens  bisher  noch  nicht 
gelungen,  B.  rugosa  oder  B.  gadi  in  Gadus  morrhua  des  Finnischen  ^Meerbusens 
aufzufinden,  obgleich  ich  zahlreiche  Exemplare  des  Dorsches  seciert  habe,  und 
obgleich  B.  rugosa  in  Lota  vulgaris  hier  oft  genug  vorkonmit.  Auch  das  scheint 
gegen  die  Identitat  der  Species  B.  rugosa  mit  B.  gadi  zu  sprechen. " 

Thus  it  is  seen  that  there  is  considerable  detailed  evidence  that  the  species 
from  Lota  is  not  the  same  as  that  from  the  marine  hosts.  One  must  then  go 
back  of  Linstow's  time  in  order  to  determine,  if  possible,  what  is  the  correct 
name  for  the  latter.  Next  in  retrogressive  order  is  van  Beneden's  (1871:56) 
description  of  A.  gadi,  confined  to  a  short  footnote  which  deals  with  little 
more  than  the  pseudoscolex.     So  far  as  it  goes  this  agrees  with  Lonnberg's 

A.  rugosum  and  with  the  material  studied  by  the  writer.  Olsson  (1867 :54)  was 
obviously  dealing  with  the  same  form  which  he  reported  from  marine  hosts  only. 
Diesing  (1863  and  1850)  copied  from  Rudolphi,  while  Cobbold  (1858)  had  the 
marine  form  before  him,  and  Baird  (1853)  had  the  fresh-water  form.  In  spite  of 
Linstow's  objection  the  writer  feels  certain  that  Dujardin  (1845)  also  had  the 
species  dealt  with  here,  especially  since  his  measurements  of  the  eggs  come 
nearest  to  those  observed  than  do  those  of  any  other  writer.  It  remains  then 
to  enquire  into  Rudolphi's  finding  and  description,  as  Leuckart  (1819 :57)  copied 
from  him  altho  at  the  same  time  remarking  that  "Ist  am  nachsten  mit  den 

B.  proboscideus  verwandt,  imd,  wenn  er  nicht  eine  Art  mit  diesem  ausmacht 
zwischen  B,  proboscideus  und  B.  sagittatus  zustellen."  For  B.  rugosus  Rudol- 
phi (1810:42)  described  a  scolex,  comparable  to  that  of  his  B.  proboscideus  and 
to  Linstow's  description  and  figure  of  the  organ,  no  neck,  and  segments  "primi 
angusti,  fere  quadrati,  insequentes  latitudinis  ratione  habita  brevissimi, 
saepeque  inequales,  vel  hinc  inde  angustiores;  margines  obtusi  crassiusculi. " 


473]  PSEUDOPHYLLIDEA  FROM  PISHES— COOPER  185 

This,  with  "neque  ovaria,  neque  foramina  articulorum  vidi  ..."  and  the 
further  fact  that  he  obtained  his  specimens  from  Gadus  lota  (  =  Lota  vulgaris), 
leads  the  writer  to  believe  that  he  was  not  dealing  with  the  form  present  in 
marine  hosts  but  with  a  form  which,  if  not  identical  with  A .  crassum  ( =  his 
B.  infundihuUformis  and  B.  prohoscideus) ,  was  very  close  to  it.  One  must  then 
go  back  farther  to  Batsch  (1786:208)  where  the  species  T.  rugosa  was  named 
on  the  basis  of  Goeze's  (1782:410)  description  of  "Der  runzlichter  Fischband- 
wurm"  from  Gadus  mustela  {  —  Motella  mustela),  the  marine  five-breared 
rockling  of  Europe,  which  the  latter  called  T.  tetragonoceps  Pallas,  with  some 
doubts,  however,  as  discussed  under  the  next  species  dealt  with  here.  Batsch 
gave  the  following  diagnosis  of  T.  rugosa: 

"Taenia  (larvata)  capite  conico  cum  corpore  subconfluente,  papillis  laterali- 
ter  adnatis  usque  ad  apicem  capitis,  eisque  binis:  articulis  brevissimis,  dila- 
tatis,  corpore  serrato." 

He  used  Goeze's  figures  1  to  4  and  pointed  out  that  he  (Goeze)  recognized 
differences  between  his  specimens  and  Pallas'  T.  tetragonoceps,  for  "Er  rechnet 
beyde  Wiirmer  fur  eine  Art,  and  die  Glieder  nebst  dem  ganzen  Korper  haben 
viel  Gleichheit,  auch  die  aussere  Gestalt  des  Kopfs.  Doch  sind  bey  diesem 
letztern  die  Saugblasen  bey  weiten  nicht  so  deutb'ch  gezeichnet,  und  stellen 
vielmehr,  wie  sich  Gotze  ausdrxickt,  zwey  Backenbarte  vor.  Die  Furche  auf 
dem  Korper  ist  auch  vorhanden,  nur  scheint  der  Korper  mehr  gestreckt,  und 
am  Rande  mehr  zackig  zu  seyn."  Consequently  the  correct  name  of  the 
species  depends  on  whether  Goeze's  description,  augmented  by  Batsch's  con- 
tributions, is  considered  to  be  applicable  to  the  material  at  hand.  The  largest 
of  Goeze's  specimens  measured  in  warm  water  a  yard  and  half  in  length  by 
scarcely  one-half  a  line  in  breadth;  but  the  latter  is  decidedly  at  variance  with 
his  figures  1  and  2  which  he  said  were  dra\\Ti  in  "natiirlicher  Grosse, "  in  which 
case  the  width  would  be  from  7  to  15  fines  and  the  scolex  about  17.5  fines  in 
length!  For  these  large  specimens — even  tho  only  the  first  set  of  measure- 
ments were  taken  into  consideration — he  described  and  figured  nothing  of 
diagnostic  value  other  than  a  scolex  provided  with  two  bothria  pretty  much  of 
the  ordinary  type,  behind  this  a  "distinctly  jointed"  and  "almost  cyfindrical" 
neck  and  along  both  surfaces  of  the  posterior  closely  crowded  segments  a 
median  longitudinal  furrow,  aU  of  which  characters  more  nearly  agree  with 
the  prohoscideus  type  of  A.  crassum  rather  than  with  the  A.  rugosum  described 
here.  And  since  the  latter  is  clearly  not  T.  tetragonoceps  Pallas  as  described 
by  Batsch  (1786:204),  the  only  course  that  seems  open  is  to  refer  the  species 
to  van  Benden's  A  hothrium  gadi.  However,  in  view  of  the  fact  that  no  material 
from  the  European  Hng  {Lota  vulgaris)  was  available  for  a  comparative  study, 
the  writer  does  not  feel  justified  in  taking  this  step,  but  here  retains  at  least 
tentatively  the  specific  name  Abothrium  rugosum  (Batsch  1786),  nee  A. 
rugosum  Goeze  1782. 

The  material  studied  consisted  of  lots  295,  296,  297,  298,  299,  300,  and  302 
from  Melanogrammus  aeglifinus  (L.),  the  haddock,  and  301  from  Gadus  cal- 
larias,  the  cod  in  the  writer's  collection;  and  17.53  in  the  collection  of  the 
University  of  Illinois,  also  from  the  cod. 


186 


ILLINOIS  BIOLOGICAL  MONOGRAPHS 


[474 


ABOTHRIUM  CRASSUM  (Bloch  1779) 
[Figs.  37-42,  50-54,  64,  77,  92] 


1779 

Taenia  crassa 

Bloch 

1779  : 

:545 

1780 

Taenia  saimonis 

MiiUer 

1780 

:  179,  202 

1781 

Taenia  tetragonoceps  (part.) 

Pallas 

1781  ; 

:87 

1782 

Taenia  capite  truncate 

Bloch 

1782 

:410 

1782 

"Der  runzlichter  Fischbandwurm" 

Goeze 

1782 

:410 

1782 

Taenia  proboscis  suilla 

Goeze 

1782 

:417 

1786 

Taenia  tetragonoceps 

Batsch 

1786 

:204 

1786 

Taenia  proboscidea 

Batsch 

1786 

:212 

1790 

Taenia  saimonis 

Gmelin 

1790 

:3080 

1790 

Taenia  salvelini 

Schrank 

1790 

:125 

1793 

Taenia  salvelini 

Schrank 

1793 

:141 

1795 

Taenia  saimonis 

Rudolphi 

1795 

:17 

1802 

Taenia  saimonis 

Bosc 

1802 

:308 

1802 

Taenia  proboscidea 

Rudolphi 

1802 

:106 

1803 

Rhytis  salvelini 

Zeder 

1803 

-.292 

1810 

Bothriocephalus  proboscideus 

Rudolphi 

1810 

:39 

1810 

Bothriocephalus  infundibuliformis 

Rudolphi 

1810  ; 

:46  • 

1816 

Bothriocephalus  proboscideus 

Lamarck 

1816 

:582 

1819 

Bothriocephalus  proboscideus 

Rudolphi 

1819 

:  137,  472 

1819 

Bothriocephalus  infundibuliformis 

Rudolphi 

1819 

:  137,  473 

1819 

Bothriocephalus  proboscideus 

Leuckart 

1819 

:38 

1819 

Bothriocephalus  infundibuliformis 

Leuckart 

1819 

:42 

1843 

Bothriocephalus  saimonis  umblae 

Koelliker 

1843 

:91 

1844 

BothriocepJuilus  proboscideus 

Bellingham 

1844 

-.252 

1844 

Bothriocephalus  inftindibuliformis 

Bellingham 

1844 

:253 

1845 

Bothriocephalus  proboscideus 

Dujardin 

1845 

:615 

1845 

Bothriocephalus  infundibuliformis 

Dujardin 

1845 

:616 

1846 

"Bothriocephalus  du  Saumon" 

Blanchard 

1847 

:116 

1850 

Dibothrium  proboscideum 

Diesing 

1850 

-.590 

1850 

Dibothrium  infundibtdiforme 

Diesing 

1850 

:590 

1853 

Bothriocephalus  proboscideus 

Baird 

1853 

:88 

1853 

Bothriocephalus  infundibuliformis 

Baird 

1853 

-.88 

1863 

Dibothrium  proboscideum 

Diesing 

1863 

:242 

1863 

Dibothrium  infundibtdiforme 

Diesing 

1863 

:242 

1867 

Botkriocephalus  proboscideus 

Olsson 

1867 

-.53 

1871 

Bothriocephalus  proboscidea 

van  Beneden 

1871 

:69 

1878 

Bothriocephalus  infundibuliformis 

Linstow 

1878 

:263 

1884 

Bothriocephalus  infundibuliformis 

Zschokke 

1884 

:21 

1889 

Bothriocephalus  suecicus 

Lonnberg 

1889 

:35 

1892 

Bothriocephalus  infundibuliformis 

Matz 

1892 

:110 

1893 

Bothriocephalus  infundibuliformis 

Olsson 

1893 

:17 

1893 

Bothriocephalus  proboscideus 

Olsson 

1893 

:17 

1894 

Bothriotaenia  inftindibtdiformis 

Blanchard 

1894 

:701 

1896 

Boihriotaenia  inftindibtdiformis 

Ariola 

1896 

:280 

1896 

Bothriotaenia  infundibuliformis 

Riggenbach 

1896  : 

:223 

1899 

Abothrium  crasstim 

Liihe 

1899  : 

:39 

1900 

Bothriotaenia  proboscidea 

Ariola 

1900  ; 

:433 

1900 

Abothrium  crassum 

Liihe 

1900a 

:97 

1909 

Bothriocephalus  proboscideus 

Scott 

1909  ; 

:78 

1910 

Abothrium  crassum 

Liihe 

1910  ; 

;26 

1910 

Abothrium  crassum 

Ward 

1910  ; 

:1184 

4751 


PSEUDOPHYLLIDEA  FROM  FISHES— COOPER 


187 


Specific  diagnosis:  With  the  characters  of  the  genus.  Large  cestodes  with 
maximum  length,  breadth  and  thickness  of  870,  6  and  2mm.,  respectively. 
Scolex  variously  shaped;  usually  rounded  posteriorly  and  truncated  anteriorly; 
with  prominent  bothria  and  terminal  disc.  First  segment  may  or  may  not  be 
elongated  to  form  a  short  neck.  Proglottides  at  first  broad  and  short  or  more 
quadrate,  cuneate  or  infundibuliform  in  shape;  in  the  middle  of  the  strobila, 
five  or  more  times  broader  than  long;  posteriorly,  quadrate  or  as  long  as  broad. 
Usually  a  median  longitudinal  groove  down  each  surface  of  the  strobila  formed 
by  emarginations  on  the  posterior  borders  of  the  segments. 

Cuticula  4  to  6iJ,  thick,  subcuticula  40  to  100/i.  Calcareous  bodies  (?)  absent 
in  adult  strobilas.  Longitudinal  muscles  not  in  bundles;  no  muscular  septa 
between  proglottides.  Nerve  strands  25  to  40iu  in  diameter,  dorsal  to  inner 
end  of  cirrus-sac.  12  chief  excretory  vessels,  6  on  each  surface  just  within 
the  transverse  muscles,  reduced  to  6  or  8  anteriorly. 

Genital  cloaca  irregularly  alternating,  but  unilateral  for  long  stretches; 
from  one-third  to  one-half  way  along  the  margin  of  the  proglottis.  Vagina 
opens  ahead  of  and  shghtly  ventral  to  the  cirrus;  no  distinct  hermaphroditic 
duct. 

Testes  within  the  nerv^e  strands,  pseudostratified,  continuous  from  joint 
to  joint;  elongated  dorsoventrally,  95  to  115  by  70  to  lOO^t;  40  to  150  in  num- 
ber. Vas  deferens  lateral,  elongated,  with  few  coils  before  entering  the  cirrus- 
sac,  350  to  600  by  100  to  180^  in  dimensions.  Cirrus-sac  ovoid  with  narrow 
end  outward,  130  to  380  by  60  to  150^1.  Cirrus  proper  an  almost  straight  tube 
in  outer  half  of  sac. 

Ovary  comparatively  small,  irregular  or  somewhat  lobed,  with  thick  isth- 
mus, 0.8mm.  wide  by  0.13  long.  Oocapt  40/i  in  diameter.  Usually  two  ven- 
tral vitelline  ducts  unite  to  form  a  common  duct  which  does  not  act  as  a  reser- 
voir. Vitelline  follicles  irregular  in  shape  and  size,  among  the  longitudinal 
muscles  or  outside  of  them,  discontinuous.  Shell-gland  small,  compact,  dorsal. 
Uterine  duct  with  only  a  few  coils  near  the  median  line.  Uterus-sac  trans- 
versely eUiptical  or  somewhat  quadrate  and  slightly  lobed,  rounded  laterally 
fiUing  up  almost  the  entire  proglottis  when  gravid;  opening  in  the  median  line 
opposite  emarginations  of  segments  ahead. 

Eggs,  45  to  115  by  30  to  75/x;  ovoid  or  eUipsoid  in  shape. 

Habitat:  In  the  pyloric  coeca  and  intestine  of  the  host. 


HOST 

LOCALITY 

COLLECTOR 

AUTHORITY 

Salmo  solar 

Borke 
Rudolphi 
Bellingham 
Dujardin 
M.  C.  V. 
Siebold  &  Johns- 
ton (Coll.  Brit. 
Mus.) 

Goeze          1782  :  417 

Salmo  solar 
Salmo  solar 
Salmo  solar 
Salmo  solar 

Gryphswald 

Ireland 

Paris 

Rudolphi     1819  :  137 
Bellingham  1844  :  253 
Dujardin     1845  :  615 
Diesing        1850  :  590 
Baird           1853  :  88 

Salmo  solar 

188 


ILLINOIS  BIOLOGICAL  MONOGRAPHS 


[476 


HOST 

LOCALITY 

COLLECTOR 

AUTHORITY 

Salmo  solar 

Warberg 

Olsson 

Olsson 

1867  :  53 

Salmo  salar 

Belgian  coast 

van  Beneden 

van  Beneden  1871  :69 

Salmo  solar 

Wamemiinde 

Zschokke 

Braim 

1891  :  55 

Salmo  salar 

Naset 

Olsson 

Olsson 

1893  :  17 

Salmo  salar 

Rhine  R.,  Basel 

Zschokke 

Zschokke 

1896  :  776 

Salmo  salar  nobilis 

Murman-Kiiste 

Zool.  Mus.,Kais. 
Akad.  Wiss., 
Petrograd 

Linstow 

1903  :  20 

Salmo  salar  sebago 

Lake  Sebago,  Me. 

Ward 

Ward 

1910  :  1184 

Salmo  alpinus 
Salmo  alpinus 

Mus.  Vienn. 

Rudolph! 
Olsson 

1819  :  137 

Jenitland 

Olsson 

1876  :  149 

Salmo  alpinus 

Lakes  Nackten, 
Storsjon,  Lock- 
nesjon 

Olsson 

Olsson 

1893  :  17 

Salmo  carpio 

L.  Garda,  Italy 

Ninni 

Stossich 

1890  :  7 

Salmo  caspius 

Karabugas-Strasse 

Maximovic 

Linstow 

1903  :  20 

Salmo  fario 

Ireland 

Bellingham 

Bellingham  1844  :  252 

Salmo  fario 

Rome 

Condorelli 

Ariola 

1900  :  435 

Salmo  fario 

Vyg-Fluss 

Danilevskij 

Linstow 

1903  :  20 

Salmo  hucho 

Mus.  Vienn. 

Rudolphi 

1819  :  472 

and  Bremser 

Salmo  lacustris 

Benaco 

Largaiolli 

Ariola 

1900  :  435 

Salmo  namaycush 

Shoal  Id.,  Lake 
Superior 

Milner 

Ariola 

1900  :  435 

Salmo  salvelinus 

Schrank 

Stiles  & 

1912  :  402 

Hassall 

Salmo  salvelinus 

Zeder 

Stiles  & 

1912  :  403 

Hassall 

Salmo  salvelinus 

Mus.  Vienn. 

Rudolphi 
Diesing 

1819  :  137 

Salmo  salvelinus 

Diesing 
Milner 

1850  :  591 

Salmo  siscowet 

Outer  Id.,  Lake 

Ariola 

1900  :  435 

Superior 

?  Salmo  thymallus 
Salmo  thytnallus  vexillifer 
Salmo  trutta 

Coll.  Vienn. 

Leuckart 

1819  :  43 

M.  C.  V. 

Diesing 
Bellinghanr 

1850  :  591 

Ireland 

Bellingham 

I  1844  :  253 

Salmo  trutta 

Coll.  Brit.  Mus. 
Olsson 

Baird 
Olsson 

1853  :  88 

Salmo  trutta 

Lakes  Storsjon, 

1893  :  17 

Halen,  Refunds- 

sjon,  Sallsjon,  & 

Ockesjon,  Jemt- 

land 

Salmo  truita 

Mumia.n-Kuste 

Zool.  Mus.  d. 
Kais.  Akad. 
Wiss.,  Petrograd 

Linstow 

1910  :  281 

Salmo  umbla 

M.  C.  V. 

Zschokke 
Zschokke 

Diesing 

Zschokke 

Zschokke 

1850  :  591 

Salmo  umbla 

1884  :  21 

Coregonus  fera 

1884  :  21 

Coregonus  lavaretus 

Lakes  Storsjon 
and  Nalden 

Olsson 

Olsson 

1893  :  17 

477] 


PSEUDOPHYLLIDEA  FROM  FISHES— COOPER 


189 


HOST 

LOCALITY 

COLLECTOR 

AUTHORITY 

Coregonus  oxyrhynchus 

Warberg 

Olsson 

Olsson         1867  :  53 

maraena 

Trutta  fario 

Genfersee,  Basel 

Zschokke 

Zschokke     1896  :  776 

Trutta  lacustris 

Rhine  R.,  Basel 

Zschokke 

Zschokke     1896  :  776 

Trutta  lacustris 

Bodensee 

Hofer 

Hofer           1904  :  221  . 

Trutta  salar 

East  Prussia 

Muehling 

Muehling     1898  :  35 

Trutta  trutta 

Wamemiinde 

Zschokke 

Braun          1891  :  55 

Trutta  variabilis 

Zschokke 

Zschokke     1884  :  21 

Thymallus  vulgaris 
Thytnallus  vulgaris 

Zschokke 

Zschokke     1884  :  21 

Storsjon,  Jemtland 

Olsson 

Olsson          1893  :  17 

Thymallus  vulgaris 

Baikal-See 

Zool.  Mus.  d. 
Kais.  Akad. 
Wiss.,  Petrograd 

Linstow       1903  :  20 

Esox  lucius 

Zschokke 
Zschokke 

Zschokke     1884  :  21 

Perca  fluviatilis 
Osmerus  operlanus 

Zschokke     1884  :  21 

Bonan,  Gestricia, 

Olsson 

Olsson         1893  :  17 

Gulf  of  Bothnia 

Clupea  harengus 

Ostsee 

Schneider 

Schneider     1902  :  28 

Lota  vulgaris 

Storsjon,  Jemt- 
land 

Olsson 

Olsson         1893  :  17 

Lota  vulgaris 

Dvina-Fluss 

Danilevskij 

Linstow       1903  :  20 

"Trout" 

Loch  Tay 

WiUiamson 

Scott            1909  :  78 

Salmo  salar 

St.  Andrews,  N.B., 

Cooper 

Cooper 

Bay  of  Fundy 

(the  present  paper) 

Cristivomer  namaycush 

Giants  Tomb  Id., 

Cooper 

Cooper 

Georgian  Bay, 

(the  present  paper) 

L.  Huron 

Cristivotner  namaycush 

Port  Credit,  Ont., 

Cooper 

Cooper 

Lake  Ontario 

(the  present  paper) 

Cristivomer  namaycush 

L.  Temagami, 

H.  B.  Ward 

Cooper 

Ont. 

(the  present  paper) 

Cristivomer  namaycush 

Charlevoix,  Mich. 

H.  B.  Ward 

Cooper 

(the  present  paper) 

Cristivomer  namaycush 

Pentwater,  Mich. 

H.  B.  Ward 

Cooper 

(the  present  paper) 

"Lota  Iota" 

Charlevoix 

H.  B.  Ward 

Cooper 

(the  present  paper) 

Lota  maculosa 

Port  Credit 

Cooper 

Cooper 

(the  present  paper) 

Lota  maculosa 

Potaganissing, 

G.  R.  LaRue 

Cooper 

and  Sitgreaves 

(the  present  paper) 

Bays,  L.  Huron 

Lota  maculosa 

Charlevoix,  Mich. 

Cooper 

Cooper 

(the  present  paper) 

Coregonus  clupeiformis 

Giant's  Tomb 

Cooper 

Cooper 

Island 

(the  present  paper) 

Coregonus  clupeiformis 

Potaganissing 

G.  R.  LaRue 

Cooper 

Bay,  L.  Huron 

(the  present  paper) 

Salvelinus  fontinaiis 

Harrietta,  Mich. 

G.  R.  LaRue 

Cooper 

(the  present  paper) 

190  ILLINOIS  BIOLOGICAL.  MONOGRAPHS  [478 

This  species,  originally  given  the  specific  name  of  Taenia  crassa  by  Bloch 
(1779^545),  was  on  the  one  hand  confused  with  A.  rugosum  and  on  the  other 
hand  given  the  new  name  Taenia  proboscis  suilla  by  Goeze  (1782:410  and  417, 
resp.)  according  as  it  was  foimd  in  Gadus  or  in  Salmo  solar.  This  confusion 
was  evidently  due  to  the  fact  that  the  latter  followed  Pallas  (1781)  in  caUing 
it  T.  tetragonoceps;  for,  as  he  said,  "Pallas  setzt  ihn  mit  Recht  I.e.  unter  die 
neuen  Arten.  [In  the  footnote,  he  considered  that  T.  tetragonoceps  Pallas, 
Taenia  crassa  Bloch  and  T.  capite  truncato  Bloch  were  all  synonymous].  Er 
hat  ihn  in  verschiedenen  Fischen,  im  Rhein-  and  Elb-lachs,  auch  in  kleinem 
Lachs  (Eriox)  am  grossten  im  Babeljau,  im  Dorsch,  in  Schollen  und  Aalen ;  der 
Graf  von  Borke  in  der  Teufelsmoraene  und  Meergrappe;  D.  Bloch  in  der  Madui- 
Moraene  und  im  Rheinlachs  gefunden."  But  in  spite  of  this,  he  expressed 
doubt  on  the  synonym  of  the  forms  from  the  Gadidae  and  from  the  Sahnonidae 
in  the  next  paragraph:  "  Da  aber  die  Zeichnungen  des  Pallas  von  der  Abbildimg 
des  D.  Blochs  von  diesem  Wurm,  so  sehr  verschieden  sind;  imd  die  letztere  die 
namliche  ist,  die  mir  der  Graf  von  Borke  von  dem  Fischwurm  aus  dem  Aal  zuge- 
schickt  hat;  so  vermuthe  ich  fast,  dass  es  dennoch  verschiedene  Arten  sind;" 
and  immediately  supported  this  contention  by  comparing-  Loewenhoek's 
"Vermes  multimembres  ex  Anguilla"  (vide  supra  =  -B.  claviceps)  vath.  Pallas 
form  and  pointing  out  differences.  Elsewhere  (p.  417)  he  described  under  the 
name  "Der  Schweinriissel  Taenia  Proboscis  Suilla:  articuUs  foliaceo  sinuosis." 
from  Salmo  salaris  L.  what  was  without  doubt  the  B.  proboscidea  of  later  \vTiters. 
Goeze's  diagnosis  of  this  form  is  as  follows: 

"Vom  Graf  von  Borke  aus  einem  siebenpfimdigem  Lachs  {Salmo  salaris 
L.).  Besonders  in  den  Blinddarmen.  Der  Kopf  wie  ein  Schweinsriissel,  mit 
vier  langlichten  flachen  Saugblasen.  Gleich  hinter  dem  Kopfe,  ohne  Hals,  die 
Blatterformigen  ausgeschweiften  GHeder.  Ich  will  nicht  mit  Gewdssheit  be- 
haupten,  dass  dies  eine  ganz  besondere  Art  sey.  So  hatte  ihn  der  Graf  von 
Borke  gesehen  und  der  Kopf  unterscheidet  sich  von  andem.  Diese  Zeichnung, 
die  ich  hier  lief  re,  war  auch  dem  Hr.  D.  Bloch,  mitgetheilet. " 

The  explanation  (p.  418)  of  the  figures  1  and  2,  Table  XXXIV,  here  referred 
to,  indicate,  incidentally,  that  he  considered  the  bothria  to  be  lateral  instead 
of  dorsoventral  in  position.  Rudolphi  (1810:39,  46,  resp.)  gave  the  first  diag- 
noses of  the  two  species,  viz.,  B.  proboscideus  and  B.  infundibuliformis,  which 
were  later  united  by  Zschokke  (1884:21)  and  Matz  (1892:110)  into  one  species, 
now  known  as  A.  crassum.  Rudolphi's  later  (1819:137)  condensed  diagnoses 
are  here  given  for  the  sake  of  comparison : 

"2.  Bothriocephalus  proboscideus  R. 

B.  capite  bothriisque  marginalibus  oblongis,  collo  nullo,  corpore  depresso 
medio  sulcato,  articuhs  brevissimis,  antrorsimi  attenuatis." 

"5.  Bothriocephalus  infundibuliformis  R. 

B.  capite  bothriisque  oblongis,  collo  nuUo,  articulis  variis,  primis  rugaefonni- 
bus,  sequentibus  subinfundibuliformibus,  reUquis  brevioribus."  In  the  same 
work  (pp.  472,  473)  he  pointed  out  resemblances  between  these  two  species  in 
that,  as  regards  B.  proboscideus,  "Specimina  maxima  in  intestinis  Salmonis 


479]  FSEUDOPBYLLIDEA  PROM  FISHES— COOPER  191 

Euchonis  reperta,  quae  Bremserus  mecum  communicavit  ad  speciem  insequen- 
tem  (praesertim  parte  anteriore)  transitum  faciunt;"  and  under  B.  infundibuli- 
formis,  the  following  species,  concerning  the  same  specimens:  "...  quae 
parte  anteriore  cum  B.  proboscideum  arguunt."  Leuckart  (1819:38,  42)  ac- 
cepted Rudolphi's  two  species  and  gave  good  figures  of  the  scolices  and  anterior 
ends  of  the  same;  but  recognized  two  forms  of  B.  proboscideus,  viz., 
"a.  CoUo  nullo;  corpore  medio  sulcato. 
Habitat  in  Salmonis  salaris  appendicibus  pylorids. 

b.  Collo  brevissimo;  corpore  medio  non  sulcato. 
Habitat  in  Salmonis  Huchonis  intestinis." 
He  further  pointed  out  and  corrected  the  errors  of  Pallas,  Bloch  and  Goeze 
regarding  the  scolex,  and  concerning  B.  infundibidiformis  said  :  "Komme  B. 
proboscideus  am  nachsten,  ist  aber  gewiss  eine  von  ihm  verschiedene  Art, 
obgleich  Bremser  .  .  .  sagt,  dass  er  beide  Arten  nicht  gem  trennen  mogte." 
Bellingham  (1844:252)  was  evidently  the  first  to  comment  on  the  relation  be- 
tween the  number  of  individuals  of  this  species  and  the  condition  of  the  host, 
when  he  said,  "  I  have  found  the  B.  proboscideus  in  such  numbers  in  the  in- 
testines and  pyloric  appendages  of  the  Salmo  salar  as  almost  completely  to 
block  up  these  parts,  which  contained  nothing  besides  but  a  white  tenacious 
mucus.  The  fish  in  which  they  were  most  nimierous  were  amongst  the  finest 
in  the  market;  which  would  help  to  prove,  that  in  these  animals  at  least,  the 
presence  of  entozoa  in  the  alimentary  canal  is  not  to  be  regarded  as  the  result 
of  disease."  He  pointed  out  the  great  variation  due  to  different  states  of 
contraction  or  relaxation  of  the  scolex  and  segments  and  also  that  B.  infundi- 
buliformis  from  Salmo  trutta  "  .  .  .  resembles  generally  the  B.  proboscideus, 
but  differs  from  it  in  some  respects. "  While  Olsson  (1867 :53)  and  Van  Beneden 
(1871:69)  found  only  B.  proboscideus,  others  recognized  Rudolphi's  two  spe- 
cies; so  that  it  remained  for  Zschokke  (1884:21-25)  to  compare  the  two  species 
in  detail  and  point  out  that  they  must  be  considered  only  different  forms  of 
the  same  species.  Later  investigations  into  the  anatomy  by  Matz  (1892 :110), 
who,  however,  studied  only  the  proboscideus  form  from  Trutta  trutta  and  Salmo 
salar,  were  considered  to  have  established  this  contention,  altho  Olsson  (1893: 
17)  still  reported  both  of  the  older  species  with  some  doubt  as  to  the  use  of 
the  name  B.  infundibuliformis.  Blanchard  (1894:701),  Ariola  (1896:280), 
and  Riggenbach  (1896 :223)  evidently  accepted  only  the  comhma.tion  Abothrium 
crassum  (Bloch)  which  is  now  generally  accepted.  Ariola  (1900:433),  however, 
called  the  species  Bothriotaenia  proboscidea  (Batsch),  thus  disregarding  the 
fact  that  Batsch  (1786:212)  renamed  Bloch's  T.  crassa. 

In  general  appearance  the  material  studied  agreed  with  the  descriptions  of 
both  B.  proboscideus  and  B.  infundibuliformis  of  the  early  writers;  for  the  for- 
mer type  from  Salmo  salar,  the  Atlantic  salmon,  would  at  first  sight  be  consid- 
ered to  belong  to  a  different  species  from  those  taken  from  the  fresh-water  hosts. 
The  largest  of  the  latter  was  one  from  a  specimen  of  Cristivomer  namaycush, 
which  measured  856mm.  in  length  by  a  maximum  breadth  of  3mm.,  while  the 
largest  from  the  salmon  measured  754mm.  in  length,  6mm.   in  maximum 


192  ILUNOIS  BIOLOGICAL  MONOGRAPHS  [480 

breadth  and  about  2min.  in  thickness.  One  from  Caregonus  clupeijormis 
measured  292  by  1.8mm.  and  another  185  by  2mm.,  while  those  from  Lota 
maculosa  were  all  small,  fragmentary  and  mostly  immature.  The  dimensions 
are  according  to  Liihe  (1910:27)  about  300mm.  in  length  by  about  1.5  to  3.5 
in  breadth;  to  Zschokke  (1884:23)  350  by  4mm.;  and  to  Ariola  (1900:435) 
250  to  400  by  2  to  4mm.  Thus  it  is  seen  that  as  regards  size  the  two  forms 
are  more  nearly  alike  in  Europe  than  here.  Consequently  one  is  not  surprised 
to  read  in  the  comparison  by  Zschokke,  "  En  effet  je  trouvais  souvent  dans  le 
m^me  poisson,  m&ne  dans  le  mSme  appendice  pylorique  des  exemplaires  dont 
les  uns  se  rapprochaient  evidenmient  du  Bothriocephalus  proboscideus,  tandis 
que  les  autres  presentaient  les  caract^res  de  Vinfundibuliformis.  Souvent 
aussi  les  caracteres  des  deux  esp^ces  etaient  reunis  sur  un  seul  mdividu,  par 
exemple  le  cou  assez  prononce  avec  des  proglottis  en  forme  de  batons,  ou  point 
de  cou  avec  les  proglottis  infundibulifomus  bien  caracterisfe. " 

In  preserved  material  the  scolex  assumes  a  great  variety  of  shapes,  from 
the  much  elongated  form  with  the  "neck"  of  Olsson  (1893:17)  and  earUer 
writers  shown  in  figure  37,  to  that  from  Salmo  salar,  shown  in  figure  39. 
Altho  the  latter  is  much  the  largest  and  apparently  quite  different  from  the 
former,  scolices  quite  like  it  excepting  for  size  were  seen  in  specimens  from  the 
lake  trout,  and  all  stages  between  these  two  extremes  were  observed.  The 
form  with  the  neck,  it  may  be  said,  is  much  more  common  in  the  youngest 
strobilas  and  plerocercoids  (Figs.  53, 54).  Regarding  this  structure  Zschokke 
(1884:24)  said  that,  "k  I'^tat  de  forte  contraction  le  cou  disparalt  presque 
compl^tement. "  Those  from  Lota  maculosa,  the  ling,  need  special  mention 
since,  as  shown  in  figure  38,  the  terminal  disc  and  anterior  half  of  the  organ 
of  fixation  is  in  many  instances  greatly  swollen  to  form  a  sort  of  pseudoscolex 
which  is  usually  found  imbedded  in  the  walls  of  the  pyloric  ceca  of  the  host 
or  often  simply  protruding  into  the  lumina  of  the  ceca.  But  this  modification 
was  found  only  in  the  older  strobilas;  in  the  younger  chains  the  scolex  is  as 
shown  in  figures  4 1 ,  42 ,  which  are  drawn  to  the  same  scale.  The  largest  with  this 
first  form  of  scolex  was  30mm.  in  length  by  1.2  in  breadth,  while  the  shortest 
with  the  swollen  end  was  20  by  1.0mm.;  so  that  somewhere  between  the  lengths 
of  20  and  30mm.  the  imbedding  of  the  scolex  with  the  concomitant  enlarge- 
ment of  the  terminal  disc  takes  place.  Several  intermediate  stages  were  seen, 
and  the  swollen  scolices  were  varied  in  shape  and  degree  of  intactness.  The 
latter  might  seem  to  point  to  the  condition  being  due  to  mechanical  or  physical 
means,  but  this  is  oflFset  by  the  fact  that  the  material  was  in  good  histological 
condition  when  sectioned. 

The  segments  also  vary  considerably  in  shape,  the  first  ones  being  in  speci- 
mens from  fresh-water  hosts  distinctly  cuneate  or  infundibuliform  and  slightly 
broader  than  long,  the  middle  ones  relatively  broader  and  shorter,  and  the 
posterior  segments  especially  in  the  older  chains  very  short  and  crowded. 
Furthermore,  in  larger  and  older  strobilas  of  the  fresh-water  form  the  posterior 
kind  of  segment,  that  is,  the  very  short  broad  form,  is  found  relatively  farther 
forward,  and  the  hinder  end  of  the  same  quite  similar,  excepting  for  size,  to 


481]  PSEUDOPHYLLIDEA  PROM  PISHES— COOPER  193 

the  worms  from  the  salmon.    In  the  latter  the  segments,  as  shown  in  figure 
39,  are  at  first  short  and  broadly  cuneate  and  at  once  become  still  shorter 
and  more  crowded.    On  the  whole  the  marine  form  of  the  species  appears  to  be 
constantly  in  a  better  state  of  nutrition  than  the  fresh-water  form.    As  the 
measurements  given  here  indicate,  the  strobila  is  much  wider  and  thicker  and 
the  scolex  much  larger;  but  what  attracts  one's  attention  at  first  sight  is  the 
clear-cut  nature  of  the  scolex  and  segments  of  this,  the  prohoscideus  type,  which 
led  BelUngham  (1844:252)  to  describe  it  as  "a  very  beautiful  species,"  as 
compared  to  the  other  form.    In  the  latter  the  posterior,  much-crowded  pro- 
glottides, especially,  are  often  irregularly  swollen  transversely  or  longitudinally 
bo  as  to  present  appearances  in  many  cases  quite  like  those  to  be  seen  in  A. 
rugosum.    Much  of  this  may,  however,  be  due  to  osmotic  action  when  the 
worms  are  near  the  point  of  death  with  the  possible  low  resistance  of  the  body- 
wall  of  the  posterior  segments  when  growth  and  development  have  gone  on  to 
such  a  stage  that  they  are  little  more  than  sacs  filled  with  eggs.    As  pointed 
out  by  various  writers  the  posterior  borders  of  the  segments  are  provided  in 
the  median  line  and  on  both  surfaces  with  a  distinct  notch  or  emargination, 
which  together  form  a  longitudinal  groove  on  each  face  of  the  chain.    This 
is  quite  pronounced  in  the  strobilas  from  the  salmon  but  often  not  so  marked 
in   those  from  the  whitefish,  lake  trout  and  ling.    In  these  it  is  confined 
more  to  the  posterior  stretches  of  the  segments  and  greatly  exaggerated  by 
the  above  mentioned  irregular  swellings  which,  however,  do  not  cross  the  longi- 
tudinal groove  formed  by  these  notches.    Often  this  groove  may  be  present 
in  the  segments  close  to  the  scolex  and  agam  in  posterior  ones  but  absent  in 
the  middle  stretches,  where,  of  course,  the  emarginations  are  either  almost 
♦ibsent  or  all  but  obUterated  by  the  degree  of  relaxation.    On  the  contrary, 
Olsson  (1893:17)  often  found  the  groove  only  in  the  middle  portions  of  the 
infundibuliformis  form.    Many  specimens  also  show  the  condition  described 
by  Leuckart  (1819:42)  w^hen  he  said,  "Die  hinteren  Rander  dieser  GUeder 
scheinen  allerdings  etwas  verdickt  und  stehen  an  den  Korperrandem  sehr 
hervor. "    In  the  anterior  segments  of  considerably  relaxed  or  especially  young 
strobilas  something  of  the  manner  of  segmentation  can  be  seen.    This  was 
found  to  take  place  much  as  in  the  genus  Bothriocephalus,  altho  the  writer 
was  not  able  to  distinguish  the  primary  segments  to  his  satisfaction.    What 
was  considered  to  be  such  is  shown  in  figure  64,  a  sketch  of  segments  beginning 
27mm.  from  the  anterior  end  of  the  strobila  in  question.    The  idea  of  domi- 
nance of  the  anterior  portions  over  the  posterior  portions  in  segmentation, 
as  brought  out  under  B.  scorpii,  is  here  shown  very  nicely.    In  the  prohoscideus 
type  of  strobila  the  same  method  of  subdivision  was  followed  in  the  anterior 
segments,  altho  with  greater  diflSculty  on  account  of  the  fact  that  the  segments 
are  so  closely  crowded  in  the  longitudinal  direction.    Olsson  (1867 :53)  noticed 
the  subdivision  of  the  segments  producing  an  alternation  of  larger  segments 
with  smaller  ones,  and  he  considered  it  to  be  an  artictdatio  spuria  similar  to 
that  described  by  Wagener  (1854:69)  for  Amphicotyle  hetero pleura  and  by 
Krabbe  (1865:384)  for  B.  scorpii  and  other  species.    Later  Olsson  (1893:17) 


194 


ILLINOIS  BIOLOGICAL  MONOGILiPHS 


[482 


states  that  transverse  divisions  occured  in  B.  infundibuliformis  as  well  as  in 
B.  proboscideus.  Finally,  as  regards  the  external  features,  it  should  be  noted 
that  the  posteriormost,  yet  ripe  proglottides  of  the  smaller  strobilas  from  the 
fresh-water  hosts  are  quadrate  in  shape,  often  as  long  as  broad,  and  usually 
somewhat  narrower  than  the  mature  segments  ahead.  These,  as  stated  by 
Olsson  (1893:17),  show  practically  nothing  more  in  the  way  of  reproductive 
organs  than  the  lobed  uterus-sacs.  The  following  measurements  of  the  scolex 
are  given  for  the  sake  of  comparison: 


HOST 

Salmo  solar 

Cristivomet  namaycush 

Lota 
maculosa 

Length 

1.01mm. 

0.70mm. 

0.87mm. 

0.71mm. 

Width  of  terminal  disc 

0.74 

0.42 

0.47 

0.41 

Width  of  bothrivim  (middle) 

0.94 

0.52 

0.38 

0.60 

Length  (laterally) 

0.88 

0.70 

0.74 

0.64 

Depth  of  terminal  disc 

0.56 

0.33 

0.44 

0.36 

Depth  posteriorly 

1.25 

0.40 

0.55 

0.68 

The  anatomy  of  the  species  was  studied  by  Matz  (1892:110),  later  writers 
referring  to  his  work,  altho  Zschokke  (1884:24),  Lonnberg  (1889:35)  and  Olsson 
(1893:17)  made  some  valuable  contributions,  while  Liihe  (1899a  and  1900a) 
dealt  with  it  from  a  comparative  standpoint.  Most  of  them,  however,  con- 
fined their  attention  almost  entirely  to  the  reproductive  organs. 

The  cuticula,  from  4  to  5/li  in  thickness,  is  divisible  into  two  layers  besides 
the  basement  membrane,  an  outer  and  darker  occupying  about  one-third  of 
the  thickness  of  the  whole,  and  quite  smooth,  and  an  inner,  quite  hght  layer. 
It  is  sHghtly  modified  on  the  posterior  borders  of  the  segments  to  form  minute 
spinelets  which  are  evidently  formed  by  the  sphtting  of  the  somewhat  thickened 
outer  layer.  This  modification  is,  however,  not  so  well  marked  as  in  other 
species.  The  subcuticula,  from  60  to  lOOfi  in  thickness,  extends  from  the 
cuticula  to  the  longitudinal  muscles,  thus  occupying  the  outer  one-haK  of  the 
cortex.  Its  nuclei  are  confined  to  its  inner  half,  thus  leaving  the  outer  ends  of 
the  cells  free.  The  whole  tissue  requires  good  fixation  and  preservation  to 
show  these  features  which  in  the  older  proglottides  and  longer  strobilas  are 
otherwise  affected  by  the  general  degeneration  coincident  with  the  development 
of  the  enormous  number  of  eggs  produced  by  this  species.  And  it  should  be 
stated  here  that  this  is  more  applicable  to  the  large  marine  form  than  to  those 
from  fresh-water  hosts.  So  far  as  the  writer  is  aware  no  calcareous  bodies 
have  been  described  for  this  species.  They  were  found  only  in  the  smallest 
strobilas  with  a  maximum  diameter  of  15/x.  The  parenchyma  is  in  the  form 
of  a  very  fiine  reticulum,  the  spaces  of  which  form  the  bulk  of  the  tissue. 

Unlike  A.  rugosum  the  longitudinal  muscles  of  the  parenchyma  are  not 
arranged  in  fasicles;  nor  do  the  transverse  fibres  form  a  septum  between  even 
the  anterior  segments.  The  latter  are  often  more  numerous  towards  the  pos- 
terior end  of  the  segments,  as  are  the  sagittal  fibres,  but  they  do  not  prevent 


483]  PSEUDOPHYLLIDEA  FROM  FISHES— COOPER  195 

the  testes  from  being  continuous  from  proglottis  to  proglottis,  nor  the  anterior 
end  of  the  uterus-sac  from  protruding  considerably  into  the  proglottis  imme- 
diately ahead.  In  the  material  from  Lota  maculosa  the  myoblastic  nuclei 
and  protoplasm  of  the  sagittal  fibres  are  almost  as  prominent  o-sin  A.rugosum. 
There  is  a  weakly-developed  series  of  external  longitudinal  muscles  arranged 
in  relation  to  the  posterior  borders  of  the  anterior  segments  as  described 
above.  The  musculature  of  the  ordinary  form  of  the  scolex  is  typical.  Trans- 
verse or  circular,  sagittal  or  radial,  and  longitudinal  muscles  are  about  equally 
developed,  the  latter  entering  the  base  of  the  organ  in  scattered  groups,  altho 
not  distinctly  fascicled,  and  extending  to  the  tip.  A  series  of  well  developed 
longitudinally  arcuate  fibres,  arranged  around  the  border  of  the  terminal  disc 
is  present,  quite  as  described  by  the  writer  elsewhere  (1914a  :92)  for  Haploboth- 
rium  globuliforme.  In  the  enlarged  scolex  from  L.  maculosa,  altho  the  general 
arrangement  of  the  musculature  is  retained,  the  number  of  fibres  is  greatly 
diminished  and  the  whole  ensemble  indicative  of  not  si  little  degeneration. 
This  is  emphasized  by  the  fact  that  in  the  unenlarged  portion  of  the  organ 
there  is  to  be  seen  in  sections  a  deposition  of  material  which  stains  much  Uke 
that  described  above  for  the  young  pseudoscohces  of  A.  rugosum.  This  is 
absent,  however,  from  the  enlarged  terminal  portion. 

In  the  form  from  the  salmon  the  chief  nerve  strands  reach  a  maximum 
dorsoventral  diameter  of  about  100/x  by  a  transverse  diameter  of  40ju.  They 
are  located  at  the  extreme  lateral  limits  of  the  medulla,  all  of  the  testes  coming 
between  them,  as  pointed  out  by  Liihe  (1900a),  and  pass  dorsal  to  the  inner 
end  of  the  cirrus-sac  and  consequently  to  the  vagina,  as  mentioned  by  Matz 
(1892:112).  In  the  scolex  the  chief  strands  enlarge  at  the  level  of  the  border 
of  the  terminal  disc  to  form  two  ganglia  which  are  united  by  a  small  transverse 
commissure,  the  whole  arrangement  being  quite  comparable  to  that  present 
in  B.  cuspidatus. 

Zschokke  (1884:25)  said  that  "Les  canaux  excreteurs  sont  paralleles  et 
voisin  des  bords  lateraux,"  while  Fraipont  (1881:12)  described  the  system 
as  follows:  "La  vesicule  terminale  est  petite.  Le  systeme  des  canaux  descen- 
dants est  fort  comphque;  ils  fournissent  des  branches  laterales  de  volume  tres 
variable;  les  unes  volumineuses,  les  autres  excessivement  greles.  Les  branches 
forment  un  reseau  a  mailles  tres  inegales.  Des  canaux  tres  fins  peuvent  partir 
directement  des  gros  troncs.  Dans  la  tete,  les  canaux  descendants  forment 
un  reticulum  tres  complique.  Cretaines  ramifications  tres  fines  se  terminent 
par  des  entonnoirs  cilies  identiques  a  ceux  du  B.  punctatus. "  In  mature  pro- 
glottides about  six  of  these  descending  canals  are  seen  on  each  surface  of  the 
strobila,  as  stated  by  Matz,  those  on  the  ventral  surface,  altho  of  varying  size, 
being  constantly  the  largest.  The  outermost  of  these  passes  ventral  to  the 
cirrus-sac,  while  the  corresponding  dorsal  one  is  much  more  median  in  position. 
AU  of  the  vessels  lie  just  within  or  sometimes  among  the  inner  transverse  mus- 
cles but  not  so  much  among  the  vitelline  follicles  as  Matz  found.  In  the  first 
segments  these  twelve  canals  become  reduced  to  three  or  four,  irregularly 
arranged  on  each  side  of  the  median  sagittal  plane,  of  which  one  or  two  may 


196  ILUNOIS  BIOLOGICAL  MONOGRAPHS  [484 

course  outside  of  the  nerve  strand  for  considerable  stretches.  Only  one  large 
vessel,  just  within  the  nerve  strand,  passes  into  the  base  of  the  scolex  on  each 
side.  These  two  are  quickly  reduced  in  size  and  disappear  at  about  the 
middle  of  the  scolex.  In  the  youngest  plerocercoids,  such  as  shown  in  figure 
50,  there  was  seen  at  the  posterior  end  a  cuticular  sac  or  invagination  about 
45/1  in  length  by  lO/x  in  diameter,  much  resembling  an  excretory  vesicle.  But 
since  no  vessels  connected  with  this  structure  as  in  yl.  rugosum,  its  nature  was 
not  satisfactorily  determined.  On  the  other  hand,  the  vessels  of  a  young  stro- 
bila  which  had  evidently  just  lost  some  segments  did  not  open  on  the  concave 
posterior  end  but  were  lost  in  the  parenchyma  some  distance  from  the  end 
after  considerable  anastomosing. 

The  earUest  traces  of  the  reproductive  rudiments  appear  in  the  marine 
type  about  45mm.  from  the  tip  of  the  scolex  while  the  first  eggs  are  to  be  seen 
ia  the  uterus  63mm.  from  the  same  point.  The  same  data  for  a  considerably 
relaxed  strobila  from  Coregonus  clupeiformis  are  respectively  62  and  225mm. 
Olsson  (1893:17)  found  the  first  testes  to  appear  in  a  200mm.  strobila  from 
Salmo  alpinus  95mm.  from  the  anterior  end,  while  20mm.  farther  the  uteri 
l)egan  to  show.  Depending  a  great  deal  on  the  amount  of  relative  contraction 
of  the  proglottides,  the  genital  cloaca  is  situated  from  one-third  to  half  way 
along  the  margin  of  the  segment,  altho  Matz  (1892:112)  stated  that  its  location 
v/as  between  the  first  and  second  thirds  of  the  edge  of  the  proglottis.  He  also 
said  that  they  (?  the  cirrus-sacs)  always  opened  on  the  left  margin  of  the 
strobila;  but  Liihe  (1899)  corrected  this  error  by  stating  that  altho  they  are 
situated  on  one  side  for  long  stretches,  in  reality  they  alternate  from  side  to 
side.  The  writer  also  found  them  to  be  irregularly  alternating  but  unilateral 
iJiru  many  proglottides.  In  one  strobila  from  a  whitefish,  for  instance,  they 
were  found  to  be  arranged  as  follows,  the  numbers  representing  the  numbers 
cif  proglottides  in  which  they  are  on  the  same  side  before  changing  to  the 
opposite  margin:  16,  3,  2,  5,  41,  21,  19,  7,  7,  8,  13,  3,  4,  11,  28,  9,  7,  9,  35,  10, 
26,  9,  7,  9,  35,  11;  while  in  a  stretch  of  gravid  proglottides  from  Cristivomer 
wamaycush,  the  lake  trout,  the  data  are:  27,  2,  80,  4,  3,  2,  13,  beyond  which 
the  cirrus-sacs  had  so  degenerated  that  it  was  found  impossible  to  follow  them 
^vith  satisfaction  in  the  toto  preparations.  Zschokke  (1884:25)  erroneously  de- 
scribed the  cirrus-pouch  as  being  "...  situee  vers  le  milieu  de  la  face  ventrale 
de  chaque  proglottis,"  while  "L'  orifice  femelle  se  trouve  en  dessous,  vers  le 
bord  posterieur  du  proglottis,"  thus  leading  Lonnberg  (1889:35)  to  establish 
the  new  species  B.  suecicus  which  Matz  (1892:111)  considered  with  obvious 
justification  to  be  synonymous  with  his  B.  infundibuliformis,  or  A .  crassum  as 
it  is  now  known.  The  cloaca  itself  is  tubular,  from  50  to  60/1  in  depth  in  the 
fresh-water  from  and  about  175/i  in  the  marine  form.  In  either  case  there  is 
no  sharply  separated  hermaphroditic  duct,  the  cirrus  and  vagina  opening  very 
close  together  at  the  bottom  of  the  pore,  the  latter  constantly  ahead  of  and  more 
or  less  ventral  to  the  former. 

Matz  stated  that  the  testes  were  about  300  in  number,  72/:  in  size,  and  ex- 
tended from  the  median  line  to  the  lateral  nerves,  while  Liihe  (1900a)  described 


485]  PSEU DOPEY LLIDEA  FROM  FISHES— COOPER  197 

them  as  being  between  the  uterus  and  the  marginal  nerves  as  in  B.  imbricaius. 
In  the  present  study  they  were  found  to  pass  to  the  median  line  and  dorsal 
to  the  uterus-sac  in  the  anterior  portion  of  the  proglottis  but  to  be  prevented 
from  doing  so  posteriorly  by  the  ovary  and  the  ducts  in  its  immediate  neighbor- 
hood. They  are  not  all  in  the  same  horizontal  plane  but  arranged  in  two  or 
three  pseudostrata  (Fig.  92) .  Their  number  is  from  40  to  150  in  each  proglottis 
with  an  average  of  90,  and  their  dimensions  from  95  to  115ai  in  depth  by  70 
to  100  in  transverse  diameter,  being  roughly  circular  in  frontal  sections.  The 
vas  deferens  forms  an  elongated  mass  of  coils  of  quite  the  same  shape  and  ar- 
rangement with  the  fewer  coils  before  entering  the  cirrus-sac  as  in  ^.  rugosum. 
Its  dimensions  are  0.35  to  0.60  by  0.15  to  0.18mm.  In  the  proximal  one-third 
to  one-half  of  the  cirrus-sac  the  male  duct  forms  a  mass  of  coils,  the  ejaculatory 
duct,  which  may  or  may  not  become  enlarged  with  sperms  to  form  at  least  a 
temporary  inner  seminal  vesicle,  while  in  the  distal  half  of  the  pouch  it  con- 
tinues in  an  almost  straight  course  as  the  cirrus  proper  with  a  maximum  dia- 
meter of  2Qn.  The  cirrus-sac  varies  in  dimensions  from  130  to  220  by  60  to 
lOS/z  in  the  fresh-water  form  and  255  to  380  by  120  to  150/*  in  the  form  froift 
Salmo  solar,  and  is  ovoid  in  shape  with  the  smaller  end,  often  quite  pointed, 
towards  the  genital  cloaca.  Matz  gave  the  length  of  the  cirrus-sac  as  255/* 
for  the  form  from  the  European  salmon  and  salmon  trout.  The  wall  is  com- 
paratively thinner  and  there  are  fewer  parenchymatous  nuclei  around  it  or 
within  it  among  the  conspicuous  retractor  muscles  than  in  A.  rugosum. 

The  vagina  opens  constantly  ahead  of  the  cirrus  and  more  or  less  ventral 
to  it  as  pointed  out  by  Matz  (p.  112).  From  this  point  it  bends  backward 
and  gradually  downward,  thus  making  a  bow  which  lies  below  the  coils  of  the 
vas  deferens,  and  then  courses  mediad  parallel  to  the  anteroventral  border  of 
the  latter.  Near  the  median  line,  however,  it  again  rises  to  pa.ss  over  the  lateral 
border  of  the  ovary  before  gaining  the  oviduct.  There  is  thus  a  broad  ventral 
bow  to  the  vagina,  which,  contrary  to  Liihe's  statement,  is  more  median  than 
in  A .  rugosum.  Opposite  the  cirrus-sac  the  vagina  may  be  found  enlarged  to 
a  diameter  of  35/i.  The  ovary  is  quite  irregular  or  only  very  roughly  kidney- 
shaped  as  stated  by  Liihe  (1900a),  and  has  a  maximmn  diameter  in  the  marine 
form  of  0.8mm.  by  a  length  of  0.13mm.  As  in  .4.  rugosum,  there  is  a  very 
broad  isthmus,  with  the  posterodorsal  part  of  which  the  oviduct  is  connected  by 
the  oocapt  which  has  a  diameter  of  40/z.  The  oviduct  receives  the  vagina 
in  the'median  coronal  plane.  Usually  two  small  vitelline  ducts  passing  along 
the  ventral  floor  of  the  medulla  unite  in  the  median  line  to  form  a  common 
duct  which  is  not  enlarged  to  form  a  reservoir;  but  in  the  material  from  Lota 
two  others  were  seen  to  unite  dorsally  to  form  another  common  duct,  while 
the  ventral  duct  formed  a  number  of  anastomoses  with  its  tributaries  before 
uniting  with  the  oviduct.  Matz  described  the  vitelline  follicles  as  irregular  in 
shape,  discontinuous  from  proglottis  to  proglottis  and  located  among  the  longi- 
tudinal muscles,  there  being  about  29  "on  the  surface,"  presumably  in  trans- 
verse sections.  The  writer  likewise  found  them  to  be  quite  irregular  in  shape  and 
to  range  in  location  from  among  the  inner  longitudinal  muscles  to  distinctly  out- 


198  ILLINOIS  BIOLOGICAL  MONOGRAPHS  [486 

side  of  them  and  even  among  the  subcuticular  nuclei  in  the  proboscideus  form. 
In  toto  moimts  of  anterior  segments  they  may  be  seen  to  be  quite  discontinuous 
and,  as  pointed  out  by  Liihe  (1900a),  arranged  in  two  lateral  fields  on  each 
surface,  there  being  a  few,  however,  in  the  median  ventral  line.  The  com- 
bined ootype  and  shell-gland  is  a  small  inconspicuous  compact  structure  lying 
close  to  the  dorsal  wall  of  the  medulla  as  in  /I .  rugosum.  The  uterine  duct  also 
takes  only  a  very  few  coils  before  expanding  into  the  capacious  uterus-sac. 
Matz  described  the  latter  as  being  not  round  as  in  B.  scorpii  and  B.  damceps, 
but  pointed  towards  each  side,  which  points  do  not  disappear  when  the  sac  is 
filled  with  eggs,  while  Liihe  (1910:17)  repeats  this  statement.  In  the  material 
studied  by  the  writer  only  the  young  uterus-sacs,  much  elongated  in  the 
transverse  direction,  were  found  to  be  pointed  laterally,  but  the  mature  struc- 
tures, i.e.,  when  filled  with  eggs,  distinctly  rounded  or  only  very  broadly  pointed 
in  some  cases  (Fig.  77).  In  dorosoventral  view  the  sac  varies  in  shape  from  an 
elliptical  or  quadrate,  lobed  organ,  filling  up  most  of  the  proglottis  in  the  fresh- 
water form,  to  a  transversely  much  elongated  cavity  in  the  proboscideus  form, 
so  enlarged  in  mature  joints  that  the  strobila  in  such  gravid  regions  is  little 
else  than  a  tube  filled  with  eggs.  The  openings  are  situated  in  the  median 
line  on  the  ventral  surface,  each  one  being  just  opposite  the  posterior  emargin- 
ation  of  the  segment  immediately,  ahead. 

Matz  states  that  the  egg  measures  54.5  by  40.9/*,  but  the  writer  found 
them  of  quite  different  sizes  when  removed  from  gravid  segments  in  the  5% 
formaUn  solution  in  which  they  were  preserved.  In  general,  two  sizes  were 
seen,  small  ones  with  thicker  darker  shells  and  larger  ones  with  thinner  lighter 
shells,  but  at  the  same  time  all  intermediate  sizes  between  these  forms.  Those 
from  the  fresh-water  form  of  the  species  measured  55  to  115  by  35  to  75/*,  while 
those  from  the  form  from  Salmo  salar  were  45  to  1 10,  by  30  to  75/x,  thus  showing 
that  so  far  as  the  size  of  the  eggs  goes,  at  least  these  two  forms  are  one  and  the 
same  species. 

So  far  as  the  writer  is  aware  the  development  of  the  egg  of  this  species  has 
been  studied  only  by  Koelliker  (1843  .-91)  and  later  by  Braun  (1889:668,  etc.) 
in  review.  Several  writers  have  described  various  young  plerocercoids.  The 
youngest  found  by  Olsson  (1867:53)  was  only  2mm.  in  length  and  had  only 
three  segments,  a  neck  and  several  longitudinal  spiral  excretory  canals,  of 
which  two  extended  to  the  anterior  part  of  the  head.  The  triangular  .caudal 
piece  of  this  yoimg  strobila  had  a  median  sinus  posteriorly,  thus  indicating, 
perhaps,  in  the  hght  of  the  present  contributions,  that  a  portion  had  already 
diasppeared.  Leuckart  (1878:605)  spoke  of  the  simplicity  of  the  development 
of  the  plerocercoid,  while  Zschokke  (1884:27)  beUeved  that  he  had  found  the 
larvae  of  B.  infundibidifonnis  in  nimierous  cysts  on  the  outside  of  the  walls  of 
the  alimentary  tract  of  Perca  fluviatilis,  TruUa  vtdgaris,  Esox  lucius,  Salmo 
umbla,  Thymallus  vulgaris  and  Lota  vulgaris.  They  were  also  found  on  the 
liver,  the  spleen,  the  ovaries  and  the  peritoneum  of  the  same  fishes,  with  their 
scoUces  ordinarily  invaginated  and  with  lengths  of  from  2  to  6mm.  In  1893 
Olsson  again  referred  to  the  plerocercoids  and  yoimger  strobilas.    In  Loia  vul- 


487]  PSEUDOPHYLLIDEA  FROM  FISHES— COOPER  199 

garis  he  found  young  strobilas,  still  possessing  the  rounded  caudal  piece  but  no 
neck,  with  the  habit  of  invaginating  their  scoHces.  In  a  Salmo  salar  he  found  on 
July  4th  similar  young  "  scolices  "  (plerocercoids)  not  only  free  in  large  numbers 
in  the  intestine  of  the  host  posterior  to  the  pyloric  ceca  but  also  present  along 
with  the  anterior  ends  of  adult  strobilas  in  the  ceca  themselves.  Again  in 
June  he  found  a  great  many  young  strobilas  in  S.  alpinus.  These  facts,  togeth- 
er with  the  further  fact  that  the  adult  worms  have  been  found  in  the  hosts 
during  every  month  of  the  year,  points  to  infection  of  the  final  host  with  the 
pleroceroids  at  all  times  of  the  year.  Of  chief  interest  in  this  connection  is 
the  finding  by  Schneider  (1902:28)  of  young  plerocercoids  2  to  7mm.  long 
free  in  the  stomach  and  intestine  of  Clupea  harengus  membras  L.,  which  he 
beheved  to  be  the  young  stages  of  Bothriotaenia  proboscidea  (Batsch),  as  he 
called  the  species.  They  were  found  in  greater  numbers  towards  the  latter 
part  of  June  than  at  other  times  during  the  summer.  Concerning  the  sig- 
nificance of  the  location  of  the  larvae  in  these  herring,  he  said:  "Daher  muss 
ich  annehmen,  dass  dieser  Fisch  nicht  der  erste,  sondem  der  zweite  Zwischen- 
wirth  des  Bandwurmes  ist.  Erster  Zwischenwirth,  in  welchem  der  Wurm  sein 
Cystenstadium  durchlauft,  muss  wohl  ein  Arthropode  (Kruster  oder  Insecten- 
larve)  sein,  der  dem  Ostseeheringe  sehr  oft  zur  Nahrung  dient.  Falls  meine 
Annahme  richtig  ist,  woran  ich  nicht  zweifele,  das  Clupea  harengus  membras 
L.  derjenige  Zwischenwirth  ist,  mit  dem  der  Ostseelachs  direct  die  Larven 
von  B.  proboscidea  in  seinen  Darmkanal  aufnimmt,  so  erklart  sich  leicht  das 
Zustandekommen  solcher  Wasserinfectionen,  wie  sie  an  den  Ostseelachsen 
beobachtet  werden. "  Liihe  (1910:12)  briefly  reviewed  the  findings  of  these 
bothriocephalid  larvae  in  various  hosts  up  to  date  and  pointed  out  that  those 
of  Diphyllobothrium  latum  have  often  been  confused  with  those  of  A .  crassum 
and  that  in  many  cases  it  is  doubtful  whether  either  was  certainly  at  hand. 
Ward  (1910:1184)  reported  the  species  from  Salmo  salar  sebago  and  Cristovomer 
namayctish,  but  was  unable  to  throw  any  Ught  on  the  life-history  altho  he  in- 
vestigated the  Sebago  smelt  as  the  possible  intermediate  host.  No  larvae  were 
found  in  the  latter,  but  concerning  the  infection  of  the  final  host,  he  said: 
''This  is  worthy  of  note  that  all  of  these  parasites  were  full  grown;  not  a 
single  specimen  was  found  which  was  not  discharging  ripe  proglottides. 
Consequently  the  infestation  must  have  taken  place  somewhat  earUer  in  the 
year. "  The  youngest  lots  of  material  studied  by  the  writer  were  two  taken 
from  Lota  maculosa  from  Lake  Ontario,  off  Port  Credit,  near  Toronto,  on 
Nov.  5  and  8, 1912,  and  one  from  the  intestine  of  a  young  Cristovomer  namaycush 
from  the  same  locality  on  the  latter  date.  The  lot  from  the  lake  trout  con- 
tained aU  stages  from  that  shown  in  figure  50  to  the  largest  which  by  compari- 
son with  adult  specimens  from  the  same  host  were  found  to  belong  to  this  species. 
While  no  stages  were  found  between  that  shown  in  figure  52  and  that  shown  in 
figure  50  altho  two  others  were  only  very  slightly  larger  than  the  latter,  it  seems 
reasonable  to  consider  the  latter  itself  to  belong  to  this  series  and  to  represent 
the  earliest  stage  of  the  same.  Figures  53  and  54,  two  later  stages,  are 
given  to  show  the  manner  of  beginning  of  the  segmentation  and  the  early 


200  ILUNOIS  BIOLOGICAL  MONOGRAPHS  [4S8 

dropping  off  of  two  or  more  very  immature  segments  from  the  hinder  end.  The 
first  indication  of  this  is  probably  represented  in  figure  52,  altho  the  strobila 
in  figure  53  does  not  show  it.  The  relative  ages,  however,  of  these  two  is 
difBcult  to  state  definitely  since  the  first  one  is  more  contracted  longitudinally 
than  the  other.  On  the  other  hand,  two  intermediate  in  length  between  those 
shown  in  figures  53  and  54,  were  indented  posteriorly,  thus  showing  that  some 
of  the  earliest  segments  had  already  been  lost.  Thus  it  is  seen  that  at  a  very 
early  period  in  the  development  of  the  strobila  of  this  species  there  are  lost 
a  few  of  the  first-formed  segments  in  much  the  same  way  as  the  bladder  of  the 
cysticercus  of  the  taenioid  cestodes  is  cast  off  in  the  final  host. 

The  material  studied  consisted  of  lots  86,  87,  88,  303  and  304  from  Salmo 
solar,  38a,  b,  c,  d,  e,  and  o,  66,  67, 164, 167  and  192  from  Cristhomer  namaycush, 
42  and  166  from  Coregonus  clupeiformis,  and  61,  62,  381,  and  387  from  Loto 
maculosa,  in  the  writer's  collection;  Ch  26a,  Ch  26b,  Ch  29a,  Ch  29b,  Ch34a, 
Tig,  T2q  and  17.186  from  C  namaycush,  and  Ch  13b  and  Ch  22b  from  Lota 
maculosa,  in  the  collection  of  the  University  of  Illinois;  and  509c,  511a,  520b, 
524a,  525a  and  530a  from  Salvelinus fontinalis,  613b  and  622d  from  Lota  macu- 
losa and  616-620c  from  "  whitefish, "  in  the  collection  of  Dr.  G.  R.  LaRue. 


489]  PSEUDOPHYLLIDEAN  CESTODES  FROM  FISHES— COOPER  201 


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Ward,  H.  B. 

1910.    Internal  Parasites  of  the  Sebago  Sahnon.  Bull.  U.  S.  Bur.  Fish.,  28: 1153-94,  1  pi. 

Weinland,  D.  F. 

1858.  Human  cestoides,  an  essay  on  the  tapeworms  of  man.    103  pp.    Camb.  (Mass.). 

WiLLEMOES-StJHM,  R. 

1869.  Helminthologisches  Notizen  I.  1.  Zur  Entmckelnag  von  Schistocephalus  dtPior- 
phus  Creplm.    Zeit.  wiss.  Zool.,  19:470-72. 

1870.  Hehninthologisches  Notizen  II.    Zeit.  wiss.  Zool.,  20:94-98,  Taf.  X. 

Wolf,  E. 

1906.  Beitrage  zur  Entwickelungsgeshichte  von  Cyathocephalus  truncatus  Pallas.  Zool. 
Anz.,  30:37^5. 

WOLEFHtjGEL,  K. 

1900.     Beitrag  zur  Kenntnis  der  Vogelhelminthen.    Diss.  (Basel),  204  pp.,  7  pi. 

Young,  R.  T. 

1913.  The  Histogenesis  of  the  Reproductive  Organs  of  Taenia  pisifortnis.  Zool. 
Jahrb.,  Anat.,  35:355^18. 

Zeder,  J.  G.  H. 

1800.  Erster  Nachtrag  zur  Naturgeschichte  der  Eingeweidewiirmer,  mit  Zufassen  und 
Anmerkungen  herausgegeben.    340  pp.,  6  pi.    Leipzig. 

1803.  Anleitung  zur  Naturgeschichte  der  Eingeweidewiirmer.  448  pp.,  4  pi.  Bam- 
berg. 

Zenecke,  E. 

1895.  Untersuchungen  iiber  den  feinem  Bau  der  Cestoden.  Zool.  Jahrb.,  Anat.,  25: 
91-161,  pi.  8-15. 


210  ILUNOIS  BIOLOGICAL  MONOGRAPHS  [498 

ZSCHOKKE,  F. 

1884.    Recherches  sur  rorganisation  et  la  distribution  zoologique  des  vers  parasites  des 

poissons  d'eau  douce.    Arch,  biol.,  5:154-243. 
1896.    Zux  Faunistik  der  parasitischen  Wurmer  von  Siisswasserfischen.     Centrbl.  Bakt. 

Parasit.,  19:772-84,  915-25. 
1903.    Die  arktischen  Cestoden.     Fauna  Arct.,  3;  31  pp.,  2  pi. 
1903a.  Marine  Schmarotzer  in  Susswasserfischen.    Verb,  naturf.  Ges.  Basel.  16:118- 

57,  2  pi. 


499] 


PSEUDOPHYLUDEAN  CESTODES  FROM  FISHES— COOPER 


211 


EXPLANATION  OF  PLATES 


ABBREVIATIONS 

be 

bothrial  cavity 

ns 

nerve  strand 

bo 

bothrial  opening 

0 

ovary 

bs 

bothrial  sphincter 

oc 

oocapt 

c 

cirrus 

od 

oviduct 

cm 

circular  muscles 

ot 

ootype 

cs 

cirrus-sac 

p 

proboscis 

cu 

cuticula 

rs 

receptaculum  seminis 

cvd 

common  vitelline  duct 

s 

subcuticula 

dh 

hermaphroditic  duct 

t 

testis 

dm 

dorsoventral  muscles 

td 

terminal  disc 

ec 

excretory  canal 

tm 

transverse  musdes 

ed 

ejaculatory  duct 

ud 

uterine  duct 

ev 

excretory  vesicle 

uo 

uterus  opening 

fa 

female  atrium 

tiS 

uterus  sac 

fd 

fertilization  duct 

ut 

uterus 

g 

genitalia 

V 

vagina 

ga 

genital  atrium 

vb 

vestibule 

gc 

ganglionic  cells 

vd 

vas  deferens 

io 

isthmus  of  ovary 

vg 

vitelline  glands 

Im 

longitudinal  muscles 

vo 

vaginal  opening 

nc 

nerve  commissure 

vs 

vesicula  seminalis 

The  lines  in  the  figures  have  the  following  values:  0.05mm.  in  figures  63,  67,  105,  106, 
107,  108;  0.2mm.  in  figures  14,  17,  18,  88,  94,  97,  99,  101;  and  0.5mm.  in  all  other  figures, 
unless  otherwise  stated  in  the  explanation  of  the  figure. 


212  JLUNOIS  BIOLOGICAL  MONOGRAPHS    ^  [500 


EXPLANATION  OF  PLATE 

Fig.   1.  Ligula  intestinalis,  anterior  end  of  larva,  showing  scolex. 

Fig.   2.  Ligula  intestinalis,  anterior  end  of  adult. 

Fig.  3.  Schistocephalus  solidus,  anterior  end  of  larva. 

Fig.  4.  Marsipometra  hastata,  scolex,  surfidal  view. 

Fig.  5.  Marsipometra  hastata,  same  specimen,  lateral  view. 

Fig.  6.  Bothrinwnus  intermedius,  scolex,  surficial  \'iew. 

Fig.   7.  Bothfitncnus  intermedius,  same  specimen,  lateral  view. 

Fig.  8.  Botkrimonus  intermedius,  same  Sf>ecimen,  terminal  view. 

Fig.  9.  Baplobothrium  globuliforme,  secondary  scolex,  surficial  view. 

Fig.  10.  Baplobothrium  globuliforme,  same  specimen,  lateral  view. 

Fig.  11.  Cyathocephalus  americanus,  scolex,  toto  preparation. 

Fig.  12.  Triaenophorus,  larva,  robustus  type,  surficial  view. 

Fig.  13.  Triaenophorus,  same  specimen,  lateral  view. 

Fig.  14.  Triaenophorus,  same  specimen,  one  of  the  tridents  of  hooks. 

Fig.  15.  Triaenophorus,  larva,  nodulosus  type,  surficial  view. 

Fig.  16.  Triaenophorus,  same  specimen,  lateral  view. 

Fig.  17.  Triaenophorus,  same  specimen,  a  trident,  terminal  view. 

Fig.  18.  Triaenophorus,  same  specimen,  surficial  view. 

Fig.  19.  Bothriocephalus  daviceps  from  Eupomotis  gibbosus,  scolex,  surficial  view. 

Fig.  20.  Bothriocephalus  daviceps,  same  specimen,  lateral  view. 

Fig.  21.  Bothriocephalus  scorpii,  scolex,  surficial  view. 

Fig.  22.  Bothriocephalus  scorpii,  same  sp>ecimen,  lateral  view. 

Fig.  23.  Bothriocephalus  daviceps  {toto.  AnguiUa  rostrata,  scolex,  surficial  view. 

Fig.  24.  Bothriocephalus  cuspidatus,  scolex,  surficial  view. 

Fig.  25.  Bothriocephalus  cuspidatus,  same  specimen,  lateral  view. 

Fig.  26.  Bothriocephalus  manubriformis,  scolex,  surficial  view. 

Fig.  27.  Bothriocephalus  manubriformis,  same  specimen,  lateral  view. 

Fig.  28.  Bothriocephalus  occidentalis,  scolex.    After  Linton. 

Fig.  29.  Clestobothrium  crassiceps,  scolex,  surficial  \-iew. 

Fig.  30.  Clestobothrium  crassiceps,  same  specimen,  lateral  view. 

Fig.  31.  Clestobothrium  crassiceps,  same  specimen,  terminal  view. 

Fig.  32.  A  bothrium  rugosum ,  scolex  of  yoimg  strobila. 

Fig.  33.  A  bothrium  rugosum,  later  stage  in  degeneration  of  same. 

Fig.  34.  Abothrium  rugosum,  stiU  later  stage. 

Fig.  35.  A  bothrium  rugosum,  pseudoscolex  from  lumen  of  pyloric  coecum  of  host. 

Fig.  36.  Abothrium  rugosum,  pseudoscolex  from  wall  of  coecum. 

Fig.  37.  Abothrium  crassum,  scolex  from  Cristivomer  namaycush. 

Fig.  38.  Abothrium  crassum,  enlarged  scolex  from  Lota  maculosa. 


ILLINOIS  BIOLOGICAL  MONOGRAPHS 


VOLUME  IV 


COOPER  PSEUDOPHYLLIDEAN    CESTODES  PLATE    I 


501J  PSEU DOPEY LUDEAN  CESTODES  FROM  FISHES— COOPER  213 


PLATE  II 


214  ILLINOIS  BIOLOGICAL  MONOGRAPHS  [502 


EXPLANATION  OF  PLATE 

Fig.  39.  A  bothrium  crassum,  scolex  of  specimen  from  Salnto  solar,  surficial  view. 

Fig.  40.  Abothrium  crassum,  same  specimen,  lateral  view. 

Fig.  41.  Abothrium  crassum,  young  scolex  from  Lota  maculosa. 

Fig.  42.  Abothrium  crassum,  same  specimen,  lateral  view. 

Fig.  43.  Haplobothrium  globuliforme,  primary  scolex,  toto  preparation. 

Fig.  44.  Haplobothrium  globuliforme,  primary  strobila,  toto  preparation. 


ILLINOIS  BIOLOGICAL  MONOGRAPHS 


VOLUME  IV 


39 


40 


COOPER 


PSEUDOPHYLLIDEAN   CESTODES 


PLATE   II 


503]  PSEU DOPEY LLI DEAN  CESTODES  FROM  FISHES— COOPER  215 


PLATE  III 


216  ILLINOIS  BIOLOGICAL  MONOGRAPHS  [504 


EXPLANATION  OF  PLATE 

Fig.  45.  Bothrimonus  itttermedius,  scolex  and  anterior  end,  toto  preparation,  showing  fore- 
most sets  of  genitalia. 

Fig.  46.  Marsipomeira  kastata,  plerocercoid,  siirficial  view. 

Fig.  47.  Marsipometra  hastata,  older  plerocercoid,  surficial  view. 

Fig.  48.  Clestobotkriutn  crassiceps,  toto  of  scolex  and  anterior  end. 

Fig.  49.  Clestobothrium  crassiceps,  toto  of  young  strobila,  surficial  vi  ew. 

Fig.  50.  Abothriutn  crassum,  plerocercoid  from  CrisHvomer  natnaycush,  surficial  view. 

Fig.  51.  Abothriutn  crassum,  same  specimen,  lateral  view. 

Fig.  52.  Abothriutn  crassum,  young  strobila  from  same  host. 

Fig.  53.  A  bothrium  crassum,  older  strobila  from  same  host. 

Fig.  54.  Abothrium  crassum,  still  older  strobila,  showing  dropping  off  of  segments  posteriorly. 


ILLINOIS  BIOLOGICAL  MONOGRAPHS 


VOLUME  IV 


COOPER  PSEUDOPHYLLIDEAN  CESTODES  PLATE  III 


505J  FSEUDOPHYLUDEAN  CESTODES  FROM  FISHES— COOPER  217 


PLATE  IV 


218  ILUNOIS  BIOLOGICAL  MONOGRAPHS  (506 


EXPLANATION  OF  PLATE 

Fig.  55.    Botkriocepkalus  scorpii,  three  anterior  primary  segments,  toto  preparation.    The 

stars  at  the  side  indicate  the  extent  of  the  segments. 
Fig.  56.    Bothriocephalus  scorpii,  one  farther  back,  also  toto. 
Fig.  57.    Bothriocephalus  scorpii,  another,  showing  reproductive  rudiments. 
Fig.  58.    Clestobothrium  crassiceps,  primary   segment   with  reproductive  rudiments,  toto 

preparation. 


ILLINOIS  BIOLOGICAL  MONOGRAPHS 


VOLUME  IV 


COOPER 


PSEUDOPHYLLIDEAN    CESTODES 


PLATE    IV 


507]  PSEUDOPHYLLIDEAN  CESTODES  FROM  FISHES— COOPER  219 


PLATE  V 


220  ILLINOIS  BIOLOGICAL  MONOGRAPHS  (508 


EXPLANATION  OF  PLATE 

Fig.  59.  Bothriocephalus  scorpii,  outline  of  mature  segments. 

Fig.  60.  Bothriocephalus  scorpii,  toto  of  same  specimen. 

Fig.  61.  Bothriocephalus  scorpii,  portion  of  strobila  showing  excretory  vessels. 

Fig.  62.  Bothriocephalus  manubriformis,  anterior  primary  segment. 

Fig.  63.  Abothrium  rugosum,  terminal  excretory  vesicle. 

Fig.  64.  Abothrium  crassum,  anterior  segments  of  strobila  from  Coregonus  clupeiformis,  toto. 


ILLINOIS  BIOLOGICAL  MONOGRAPHS 


VOLUME  IV 


COOPER 


PSEUDOPHYLLIDEAN    CESTODES 


PLATE    V 


5091  PSEU DOPEY LLI DEAN  CESTODES  FROM  FISHES— COOPER  221 


PLATE  VI 


222  ILUNOIS  BIOLOGICAL  MONOGRAPHS  [510 


EXPLANATION  OF  PLATE 

Pig.  65.    Haplobotkriufn  globuliforme,  transection  thru  primary  scolex. 

Fig.  66.    Haplobotkriutn  globuliforme,  transection  thru  the  ganglionic  mass  behind  the  pro* 

boscides.    The  reference  line  is  0.1mm.  long. 
Fig.  67.    Haplobotkrium  globuliforme,  transection  thru  a  single  proboscis  bulb. 
Fig.  68.    Marsipometra  kastata,  toto  of  ripe  proglottis. 
Pig.  69.    Botkriocephalus  cuspidatus,  transection  thru  an  anterior  segment. 
Fig.  70.    Botkriocephalus  cuspidatus,  toto  of  ripe  proglottides,  posterior  in  deeper  optical 

section. 


ILLINOIS  BIOLOGICAL  MONOGRAPHS 


VOLUME  IV 


COOPER 


PSEUDOPHYLLIDEAN    CESTODES 


PLATE  VI 


511]  PSEUDOPHYLLIDEAN  CESTODES  FROM  FISHES-COOPER  223 


PLATE  VII 


224  ILUNOIS  BIOLOGICAL  MONOGRAPHS  \SU 


EXPL.\NATION  OF  PLATE 

Fig.  71.  Bothriocephalus  scorpii,  toto  of  two  segments. 

Fig.  72.  Bothriccephalus  claviceps  from  Eupomoiis  gibbostu,  toto  of  mature  proglottides. 

Fig.  73.  Bothriocephalus  manubriformis,  toto  of  mature  proglottides. 

Fig.  74.  Ckstobothriutn  crassiceps,  segments  showing  spurious  articulations. 

Fig.  75.  CUstobotlirium  crassiceps,  toto  of  mature  proglottis. 

Fig.  76.  Abothrium  rugosum,  frontal  section  of  mature  proglottis. 

Fig.  77.  Abothrium  crassum,  toto  of  ripe  proglottis  of  strobila  from  Coregonus  clupeiformis. 


ILLINOIS  BIOLOGICAL  MONOGRAPHS 


VOLUME  IV 


74 


75 


uo 


COOPER 


PSEUDOPHYLLIDEAN    CESTODES 


PLATE  VII 


513]  PSEUDOPHYLLIDEAN  CESTODES  FROM  FISHES— COOPER  225 


PLATE  VIII 


226  ILUNOIS  BIOLOGICAL  MONOGRAPHS  f5M 


EXPLANATION  OF  PLATE 

Fig.  78,     Ligtda  intestinalis,  median  portion  of  a  transection  thru  the  genital  cloaca. 

Fig.  79.    Sckistocephdtis  solidus,  median  portion  of  transection  thru  ovary. 

Fig.  80.    Schistocephalus  solidus,  median  portion  of  transection  thru  the  seminal  vesicle  and 

cirrus-sac.    The  reference  line  is  0.3nam.  long. 
Fig.  81.    Bothrimonus  iniermedius,  transection  thru  the  ovarian  isthmus. 


ILLINOIS  BIOLOGICAL  MONOGRAPHS 


VOLUME  IV 


78 


COOPER 


PSEUDOPHYLLIDEAN  CESTODES  PLATE  VIII 


5151  PSEUDOPHYLLIDEAN  CESTODES  FROM  FISHES— COOPER  227 


PLATE  IX 


228  ILUNOIS  BIOLOGICAL  MONOGRAPHS  [516 


EXPLANATION  OF  PLATE 

Fig.  82.  Cyathocephdus  amerkanus,  transection  thru  ovarian  isthmus. 

Fig.  83.  Marsipometra  hastata,  transection  thru  ovarian  isthmus. 

Fig.  84.  Bothriocephalus  scorpii,  transection  thru  ovary. 

Fig.  85.  Bothriocephalus  daviceps  from  EupomoHs  gibbosus,  transection  thru  ovaiy. 

Fig.  86.  Bothriocephalus  cuspldatus,  transection  thru  ovary  of  mature  proglottis. 


ILLINOIS  BIOLOGICAL  MONOGRAPHS 


VOLUME  IV 


COOPER 


PSEUDOPHYLLIDEAN   CESTODES  PLATE    IX 


|tt71  PSEU DOPEY LLI DEAN  CESTODES  FROM  FISHES— COOPER  229 


PLATE  X 


230  ILWINIS  BIOLOGICAL  MONOGRAPHS  |S1I 


EXPLANATION  OF  PLATE 

Fig.  87.  Boihriocephalus  manubriformif,  transection  thru  anterior  region. 

Fig.  88.  Boihriocephalus  manubriformis ,  cirrus-sac  and  vaginal  bulb  from  a  transection. 

Fig.  89.  Boihriocephalus  occidentalis,  cirrus-sac  from  a  transection.     The  reference  line  it 

0.1mm.  long. 

Fig.  90.  Clesiobothrium  crassiceps,  transection  thru  the  ovary. 

Fig.  91.  Ahothrium  rugosum,  transection  thru  the  ovary. 

Fig.  92.  Abothrium  crassutn,  transection  thru  the  ovary  of  a  specimen  from  Salmo  solar. 


ILLINOIS  BIOLOGICAL  MONOGRAPHS 


VOLUME  IV 


ns 


COOPER  PSEUDOPHYLLIDEAN   CESTODES  PLATE  X 


519)  PSEUDOPHYLUDEAN  CESTODES  FROM  FISHES-~COOPER  231 


PLATE  XI 


2»  ILUNOIS  BIOLOGICAL  MONOGRAPHS  [520 


EXPLANATION  OF  PLATE 

Fig.  93.    Cyalhocephalus  americanus,  frontal  section  of  ripe  proglottis. 

Fig.  94.    Botkrimonus  inUrmedius,  median  sagittal  section. 

Fig.  95.    Bothriocephalus  scorpii,  median  sagittal  section,  composite.    The  reference  line  is 

0.3mm.  long. 
Fig.  96.    Bothriocephalus  claviceps  from  Eupomotis  gibbosus,  median  sagittal  section. 
Fig.  97.    Bothriocephalus  manubriformis,  transection  thru  uterus  opening. 


ILLINOIS  BIOLOGICAL  MONOGRAPHS 


VOLUME  IV 


COOPER 


PSEUDOPHYLLIDEAN   CESTODES  PLATE   XI 


5211  PSEUDOPHILLIDEAN  CESTODES  FROM  FISHES-COOPER  233 


PLATE  XII 


234  ILUNOJS  BIOLOGICAL  MONOGRAPHS  (522 


EXPLANATION  OF  PLATE 

Fig.  98.     Ligula  itUestitudis,  union  of  vagina  and  vitelline  duct  with  oviduct.    The  reference 

line  is  0.1mm.  long. 
Fig.  99.    Cyaihocephalus  atnericanus,  oocapt  containing  an  ovum. 
Fig.  100.  Marsipometra  hastate,  genital  cloaca  from  frontal  section. 
Fig.  101.  Marsipomelra  hastata,  cirrus  sac  from  a  transection. 
Fig.  102.  Botkriocephalus  cuspidatus,  median  sagittal  section,  composite. 
Fig.  103.  CUsiobotkrium  crassiceps,  median  sagittal  section,  composite. 


ILLINOIS  BIOLOGICAL  MONOGRAPHS 


VOLUME  IV . 


uo 


COOPER  PSEUDOPHYLLIDEAN  CESTODES  PLATE  XII 


523]  PSEUDOPHYLUDEAN  CESTODES  FROM  FISHES— COOPER  235 


PLATE  XIII 


236  JLUNOIS  BIOLOGICAL  MONOGRAPHS  [524 


EXPLANATION  OF  PLATE 

Fig.  104.    Cyatkocephalus  americanus,  diagram  of  median  sagittal  section. 

Fig.  105.     Bothriocephalus  scorpii,  portion  of  section,  showing  imion  of  vagina  with  oviduct. 

Fig.  106.  Bothriocephalus  cuspidalus,  young  egg,  showing  an  early  stage  in  development, 
drawn  from  life. 

Fig.  107.    Bothriocephalus  cuspidalus,  older  egg,  many-celled  stage. 

Fig.  108.  Clestobothrium  crassiceps,  four  consecutive  sections  thru  union  of  vagina  and  ovi- 
duct, showing  the  receptaculum  seminis. 

Fig.  109.  Abothrium  rugosum,  union  of  va^Jia  and  common  vitelline  duct  with  oviduct. 
The  reference  line  is  0.02mm.  long. 


ILLINOIS  BIOLOGICAL  MONOGRAPHS 


VOLUME  IV 


108 


^cs 

• 

^/« 

o 

•- 

10 

{"^ 

j^ff?;^;;^ 


rs 


/04 


109 


COOPER 


PSEUDOPHYLLIDEAN  CESTODES 


PLATE  XIII 


525] 


PSEUDOPHYLLIDEA  FROM  FISHES— COOPER 


237 


INDEX  OF  HOSTS 


Abramis  bjorkna,  23 

blicca,  23 

brama,  21 

vimba,  23 
Acipenser  oxyrhynchus,  64 

ruthenus,  99 

sturio,  64 
Albumus  albumus,  23 

lucidus,  21 
Alca  pica,  34 

torda,  33 
Alosa  ohiensis,  21 
Ambloplites  rupestris,  22 
Ambystoma  sp.,  22 

tigrinum,  22 
Ameiurus,  21 
Amia,  71 
Amia  calva,  45 
Amoetes  branchialis,  23 
Anas  boschas  fera,  22 

glacialis,  33 
Anguilla  acutirostris,  116 

anguilla,  116 

migratoria,  116 

rostra  ta,  116 

vulgaris,  99,  116 
Aquila  chrysaetus,  22 
Ardea  alba,  23 

ciconia,  23 

cinerea,  34 

egretts,  23 

nycticorax,  22 
steliaris,  33 
Amoglossus  boscii,  98 

pegosa,  98 

solea,  98 
Aspius  albumus,  23 

rapax,  21 
Atherina  mocho,  21 

B 
Bass,  white,  87 
Blicca  bjorkna,  21 
Bothus  maculatus,  99 
Brochet,  83 

C 
Carassius  carassius,  23 

gibelio,  21 


vulgaris,  23 
Catostomus  ardens,  21 

commersonii,  25,  85,  87 
commersonii  commersonii,  22 

latipinnis,  21 
Chondrostoma  nasus,  21 
Ciconia  alba,  22,  33 

ciconia,  23,  34 

nigra,  34 
Clupea  harengus,  189 

harengus  membras,  199 
Cobitis  aculeata,  23 

taenia,  21 
Colymbus  arcticus,  22,  34 

auritus,  23 

crista tus,  23,  34 

glacialis,  34 

griseigena,  23,  34 

hoelbeelli,  23 

immer,  34 

rubricollis,  23 

septentrionalis,  33 

subcristatus,  23 

troile,  34 
Coregenus  albula,  83 

clupeiformis,  54,  189 

fera,  188 

lavaretus,  83,  188 

oxyrhynchus  maraena,  189 

wartmanni,  21 
Corvus  corax,  34 

comix,  22,  33 
Cottus  bairdii,  33 

bubalis,  98 

poecilopus,  33 

quadricomis,  98 

Scorpio,  33 

scorpius,  97,  98 
Cristivomer  namaycush,  189 
Cyprinus  albumus,  21 

blicca,  23 

brama,  23 

carassius,  23 

gobelio,  23 

lacustris,  23 

leuciscus,  23 

tinea,  23 


238 


ILLINOIS  BIOLOGICAL  MONOGRAPHS 


[S26 


D 
Decapterus  punctatus,  99 

E 
Esox  lucius,  21,  83,  84,  86,  189 

masquinongy,  85,  87 
Eupomotis  gibbosus,  116 

F 
Falco  albicilla,  22 

chrysaetos,  23 

tulvus,  23 
Fulica  atra,  33 
Fuligula  clangula,  22 

marila,  33 

G 
Gadidae,  178 
Gadus  aeglifinus,  98,  173 

callarias,  173,  174 

euxinus,  155 

lota,  173 

merluccius,  155,  173 

minutus,  98 

morrhua,  173,  174 

morrua,  183 

mustela,  173 

pollacbius,  174 
Gammarus  pulex,  61 
Gasterosteus  aculeatus,  33 

bispinosus,  116 

bispinosus  atkinsii,  22,  33 

cataphractus,  33 

pungitius,  33 
Gobio  fluviatilis,  23 

gobio,  21 

vulgaris,  21 
Graculus  carbo,  22 

H 
Haematopus  ostrealegus,  33 
Hake,  small,  155 
Haliaetus  albicilla,  22 
Harelda  glacialis,  33 
Hemitripterus  americana,  99,  100 
Herodias  alba,  22 
Herring,  lake,  86 
Hiodon  alosoides,  124 

tergisus,  124 
Hippoglossus  hippoglossus,  99 
Histiophorus  gladius,  134,  146 

sp.,  134 
Hybognathus  nuchalis,  21 
Hydrochelidon  nigra,  22 

I 
Istiophorus  nigricans,  134 

L 
Labrus  maculatus,  99 


Larus  argentatus,  22,  34 

canus,  23 

capistranus,  34 

marinus,  34 

melanocephalus,  23 

parasiticus,  23 

pelecanus  carbonis,  23 

pygmaei,  23 

ridibundus,  33 

tridactylus,  23 
Leucichthys  artedi,  83,  84,  86 
Leuciscus  erythrophthalmus,  23 

leuciscus,  23 

phoxinus,  23 

pulchellus,  23 

rutilis,  21 

vulgaris,  23 
I^imanda  ferruginea,  99 
Lophodytes  cucullatus,  33 
Lophopsetta  maculata,  99 
Lota,  178 
Lota  lota,  189 

maculosa,  41,  86,  189,  194 

molva,  183 

vulgaris,  99,  174,  189 
Lucioperca  lucioperca,  23 

Sandra,  21 

M 
Melanogrammus  aeglifinus,  174 
Merganser,  22 
Merganser  merganser,  23,  34 

sp.,  23 
Mergus  albellus,  23,  34 

merganser,  22 

minutus,  23 

serrator,  22,  33 
Merlangus  carbonarius,  155,  174 

pollachius,  183 

sp.,  155 
Merluccius  bilinearis,  112,  155,  170 

esculentus,  155 

merluccius,  155 

vulgaris,  155,  174 
Microgadus  tomcod,  63,  174 
Micropterus  dolomieu,  22,  85,  87 
Mola,  91 
Mola  mola,  92 
Morrhua  aeglifinus,  174 

americana,  21 

vulgaris,  174 
Motella  mustela,  99,  183 
Mullus  barbatus,  99 
Muraena  anguilla,  116 

cassini,  116 


527] 


PSEUDOPHYLUDEA  FROM  FISHES— COOPER 


239 


Myoxocephalus  aeneus,  99,  100 
groenlandicus,  100 
octodecimspinosus,  99 

■     N 
Nemachilus  strauchi,  21 
Notropia  cayuga,  22 

comutus,  21,  22 

delicatus,  87 

hudsonius,  22 
Nycticorax  nycticorax,  22 
Nyroca  marila,  33 

O 

Osmerus  mordax,  21 
operlanus,  189 


Paralichthys  dentatus,  99 

oblongus,  99 
Palinurichthys  perciformis,  99 
Perca  flavescens,  22,  87,  124 

fluviatilis,  21,  189 
Percina  caprodes,  124 
Petromyzon  branchialis,  21 
Phoca  vitulina,  21,  33 
Pickerel,  124 
Platessa  flesus,  98 

passer,  98 

plana,  98 
Pleuronectes  boscius,  98 

flesus,  98 

maximus,  98 

rhombus,  98 

solea,  98 
Podiceps  auritus,  22 

cristatus,  24,  34 

minor,  23 

nigricollis,  33 

rubricoUis,  23,  34 
Podilymbus  podiceps,  23 
Polyodon,  71 
Polyodon  spathula,  72 
Pomatomus  saltatrix,  155 
Pomolobus  aestivalis,  170 
Pontoporeia  hoyi,  61 
Poronotus  triacanthus,  112 
Psetta,  maxima,  98 

Pseudopleuronectes  americanus,  64,  99 
Puffinus  kuhli,  33 

R 
Raja  clavata,  99 
Rana  esculenta,  33 
Recurvirostra  avocetta,  33 
Rhombus  barbue,  99 


laevis,  99 
maximus,  98,  99 
moeoticus,  99 
Rhynchichthys  gronovii,  33 
Rissa  tridactyla,  22 
Rock  cod,  149 

S 
Salmo  alipinus,  1S8 
carpio,  188 
caspius,  188 
fario,  188 
hucho,  188 
lacustris,  188 
namaycush,  188 

salar,  33,  113,  183,  187,  188,  189,  194 
salaris,  190 
salar  nobilis,  188 
salar  sebago,  188 
salvelinus,  21,  188 
siscowet,  188 
thymallus,  188 
thymallus  vexillifer,  188 
trutta,  188 
umbla,  188 
Salvelinus  fontinalis,  189 
Scardinius  erythrophthalmus,  21 
Schizopygopsis  kozlovi,  21 
Scomber  scomber,  100 
Scorpaena  porcus,  99,  113 

scrofa,  112 
Scyllium  canicula,  163 
Sebastodes  sp.,  149 
Siluris  glanis,  21 
Solea  monochii,  99 
Squalius  cephalus,  21 

turcicus,  23 
Stercorarius  parasitica,  22,  33 
Sterna  arctica,  34 
hirundo,  22,  33 
macroura,  34 
minuta,  34 
nigra,  23,  34 
Stizostedion  canadense,  85,  87,  124 

vitreum,  86,  87,  124 
Sunflsh,  91 

T 
Tarpon  atlanticus,  134,  145 
Tetrapterus  albidus,  134 
belone,  134 
imperator,  134 
sp.,  145 
Thymallus  vulgaris,  189 
Tinea  vulgaris,  21 
Torpedo  ocellata,  98 


2  JO 


ILLINOIS  BIOLOGICAL  MONOGRAPHS 


Totanus  calidrus,  33 

chloropus,  23 
Trachurops  crumenophthalmus,  100 
Trigla  adriatica,  98 

lineata,  98 
Trout,  189 
Trutta  fario,  189 

lacustris,  189 

salar,  189 

trutta,  189 

variabilis,  189 

vulgaris,  198 


U 

Una  grylle,  34 

troile,  33 
Uranidea  formosa,  33 
Urinator  arcticus,  22,  33 

stellatus,  23 
Urophycis  chuss,  100 

tenuis,  174 

X 
Xema  minutum,  22 

ridibundum,  23 
Xiphias  gladius,  91 


529] 


PSEUDOPHYLLIDEA  FROM  FISHES— COOPER 


241 


INDEX 


Abothrium,  171,  176 

Abothrium  crassum,  12,  78,  176  186 

gadi,  172 

rugosum,  12,  74,  172,  193 
Acanthocephala,  51 
AcanthophalHdae,  15 
Acrobothrium,  53 
Alyselminthus,  95 
Alyselminthus  bipunctatus,  96 
Amphicotyle,  171 

Amphicotyle  heteropleura,  159,  193 
Amphicotylinae,  12  171 
Amphitretidae,  15 
Anchistrocephalus,  70 
Anonchocephalus,  70 
Aprocta,  9 

B 
Bothriudium,  16,  70 
Bothridium  pithonis,  16 
Bothrimonus,  11,  62 
Bothrimonus  cohaerens,  64 

fallax,  64,  66 

intermedius,  11,  63 

nylandicus,  60,  63,  64 

pachycephalus,  60,  64 

sturionis,  62,  64 
Bothriocephalidae,  9 
Bothriocephalidea,  9 
Bothriocephalus,  95 
Bothriocephalus  affinis,  113 

angustatus,  114 

bipunctatus,  96 

claviceps,  12,  101,  198,  114 

crassiceps,  154 

cuspidatus,  12,  94,  123,  135,  195 

dubius,  101 

du  Saumon,  186 

tasciatus,  101 

gadi  merluccii,  163 

histiophorus,  133,  147 

imbricatos,  197 

infundibuliformis,  185,  186 

laciniatus,  133,  145,  150 

manubriformis,  12,  133,  145,  147,  149 

neglectus,  158 

nodosus,  31 

occidentalis,  12.  145,  149 


pilula,  154 

plicatus,  89 

proboscideus,  176,  186 

punctatus,  96,  112,  118,  195 

punctatus  forma  bubalidis,  96 
forma  cottiquadricomis,  96 
forma  motellae,  96 
forma  punctatus  vel  typica,  96 
forma  rhombi,  96 

rugosus,  172 

sagittatus,  184 

salmonis  umblae,  186 

scorpii,  12,  43,  49,  93,  96,  112,  119,  125, 

135,  152,  159,  193 

scorpii  forma  bubalidis,  112 
forma  motellae,  112 

semiligula,  19 

solidus,  30 

spiraliceps,  164 

suecicus,  186 

truncatus,  89 

variabilis,  101 

zschokkei,  31 
Bothriotaenia,  70,  88,  184 
Bothriotaenia  gadi,  184 

hastata,  71 

infundibuliformis,  186 

plicata,  89 

proboscidea,  183,  186 

rugosa,  172 

C 
Caryophyllaeidae,  7,  13 
Cephalocotylea,  9,  62 
Cephalocotyleum,  53 
Ceatoda,  10 
Cestodaria,  10 
Cestodes,  9 

Clestobothrium,  12,  153 
Clestobothrium  crassiceps,  12,  65,  94,  103, 
140,  154 

Cyathocephalinae,  11,  53,  88 
Cyathocephalus,  11,  53,  70 
Cyathocephalus  americanus,  11,  53,  66 

catenatus,  56 

truncatus,  42,  53 
Cysticercus,  81 
Cysticercus  fasciolaris,  170 


242 


ILUNOIS  BIOLOGICAL  MONOGRAPHS 


[540 


-       D 
Dibothriocephalinae,  88 
Dibothriorhynchus  ruficoUis,  51 
Dibothrium,  17,  70,  88,  95,  153,  171 
Dibothrium  angustatum,  112 
belones,  163 
claviceps,  114 
crassiceps,  154 
hastatum,  71 
heteropleunim,  159 
infundibuliforme,  186 
laciniatum,  133,  145,  1^7 
ligula,  18,  19,  31 
manubriforme,  133 
microcephalum,  101 
occidentale,  149 
plicatum,  89,  136 
probosddeum,  186 
punctatum,  96 
rugosum,  172 
Dibothrius,  95,  153 
Diphyllobothriidae,  11,  15,  93 
Diphyllobothriinae,  42,  70 
Diphyllobothrium,  70 

Diphyllobothrium  latum,   15,  42,  80,   199 
Diplocotyle,  62 
Diplocotyle  cohaerens,  64 
olrikii,  64 
rudolphii,  56,  64 
serrata,  (A 
Disymphjlobothrium,  62 

E 
Echinococcifer,  14 
Echinorhj-nchus,  53 
Edunorhynchus  xiphiae,  89 

F 
Fasciola,  17,  30 
Fasciola  abdominalis,  18 

hepatica,  30 

mtestinalis,  18 
Fimbriaria  fasciolaris,  107 
Fistulicola,  11,  88 
Fistulicola  plicatus,  11,  89 


Gymnobothria,  9 


H 


Haematoloechus  asper,  161 

Halysis,  30 

Halysis  lanceolato  nodosa,  31 

Haplobothriinae,  11,  13,  15,  42,  70 

Haplobothrium,  11,  13,  15,  43,  71,  93 

Haplobothrium  globulifonne,  7,  11    15    44 

74.104,160,195  '      ' 


Hirudo,  30 

BBrudo  depressa  alba,  30 

L 
Ligula,  17,  42 
Ligula  abdominalis,  18 

abdominalis  albumi,  18 
abdominalis  bramae,  18 
abdominalis  carassii,  18 
abdominalis  cobitidis,  18 
abdominalis  cjprinorum,  18 
abdominalis  gobionis,  18 
abdommalis  leucisci,  18 
abdominabs  trincae,  18 
abdominalis  vimbae,  18 
acuminata,  18 
albumi,  18 
altemans,  19 
avium,  18,  19 
bramae,  18 
carassii,  18 
catostomi,  18 
cingulum,  18 
cobitidis,  18 
colymbi,  18,  19 
constringens,  18 

contortrix,  18 

crispa,  18 

digramma,  18,  19 

edulis,  18 

gobionis,  18 

interrupta,  19 

intestinalis,  11,  17,  18,  19,  39 

leucisci,  18 

monogramma,  18,  19 

nodosa,  19 

petromyzontis,  18 

piscium,  18 

reptans,  19 

salvelini,  18 

simplicissima,  18,  19 

sparsa,  19 

trincae,  18 
uniserialis,  19 
vimbae,  18 
Ligulinae,  11,  16.  70,  88 

M 
Marsipometra,  12,  16,  70,  93 
Marsipometra  hastata,  7,  12,  71 
Marsipometrinae,  12,  15,  70 
Monobothrium,  53 


Nemertini,  51 


N 


541] 


PSEUDOPHYLLIDEA  FROM  FISHES— COOPER 


243 


Proteocephalus,  163 
Pseudophyllidea,  13,  IS,  118 
Ptychobothriidae,  12,  15,  43,  70,  79,  93,  166 
Ptychobothriinae,  12,  80,  94 

R 

Rhytelminthus,  81,  95 
Rhytelminthus  anguillae,  114 
Rhytis,  30,  81,  95,  171 
Rhytis  bipunctata,  96 

claviceps,  114 

conoceps,  172 

salvelini,  186 

solida,  30 

S 
Schistocephalus,  8,  11,  17,  26,  30,  42,  137 
Schistocephalus  dimorphus,  9,  31 

gasterostei,  31 

nodosus,  31 

rhynchichthydis,  31 

solidus,  11,24,30,31 

zschokkei,  31 
Schistorh)Tichus  dimorphus, 
Scolex  polymorphus,  133 
Scyphocephalus,  16 

T 
Taenia,  17,  18,  30,  53,  81,  88,  95,  171 
Taeniae,  105 
Taenia  acutissima,  30 

anguillae,  114 

capita  ta,  18 

capite  truncate,  186 

cingulum,  18 


claviceps,  114 

crassa,  186 

decimpollicaris,  172 

gasterostei,  30,  31 

haeruca,  89 

lata,  30 

lanceolata  nodosa,  31 

lanceolata  var.  |3  31, 

nodularis,  31 

proboscidea,  186 

proboscis  suilla,  186 

punctata,  96 

rugosa,  172 

salmonis,  186 

salvelini,  186 

scorpii,  96 

solida,  30 

tetragonoceps,  172,  186 

truncata,  57 
Taenioidea,  51 
Tetraphyllidea,  51 
Tetrarhynchus,  51 
Tetrarhynchus  longicollis,  51 
Triaenophorinae,  10,  11,  16,  45,  70,  81 
Triaenophorus,  11,  42,  70,  81,  82 
Triaenophonis  nodulosus,  80,  82 

robustus,  82 
Tricuspidaria,  81 
Trypanorhyncha,  13,  42, 45 


Vermis  multimembris,  114 

miiltimembris  rhombi,  96 
Vesicaria,  81 


UNIVERSITY  OF  ILLINOIS-URBANA 

570  SILL  C004 

i'-JjJjOJS^B'OLOGICAL  MONOGRAPHS  URBANA 


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